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CIS Cisco IOS 15 Benchmark v4.0.0

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CIS Cisco IOS 15 Benchmark
v4.0.0 - 06-30-2015
http://benchmarks.cisecurity.org
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Table of Contents
Table of Contents .................................................................................................................................................. 2
Overview .................................................................................................................................................................. 7
Intended Audience ........................................................................................................................................... 7
Consensus Guidance........................................................................................................................................ 7
Typographical Conventions ......................................................................................................................... 8
Scoring Information ........................................................................................................................................ 8
Profile Definitions ............................................................................................................................................ 9
Acknowledgements ...................................................................................................................................... 10
Recommendations ............................................................................................................................................. 11
1 Management Plane .................................................................................................................................... 11
1.1 Local Authentication, Authorization and Accounting (AAA) Rules ............................... 11
1.1.1 Enable 'aaa new-model' (Scored) ....................................................................................... 12
1.1.2 Enable 'aaa authentication login' (Scored) ..................................................................... 14
1.1.3 Enable 'aaa authentication enable default' (Scored) .................................................. 16
1.1.4 Set 'login authentication for 'line con 0' (Scored) ........................................................ 17
1.1.5 Set 'login authentication for 'line tty' (Scored) ............................................................. 19
1.1.6 Set 'login authentication for 'line vty' (Scored) ............................................................ 21
1.1.7 Set 'aaa accounting' to log all privileged use commands using 'commands 15'
(Scored) ................................................................................................................................................... 23
1.1.8 Set 'aaa accounting connection' (Scored) ........................................................................ 24
1.1.9 Set 'aaa accounting exec' (Scored) ..................................................................................... 26
1.1.10 Set 'aaa accounting network' (Scored) .......................................................................... 28
1.1.11 Set 'aaa accounting system' (Scored) ............................................................................. 30
1.2 Access Rules ........................................................................................................................................ 31
1.2.1 Set 'privilege 1' for local users (Scored) .......................................................................... 32
1.2.2 Set 'transport input ssh' for 'line vty' connections (Scored).................................... 33
1.2.3 Set 'no exec' for 'line aux 0' (Scored) ................................................................................ 34
1.2.4 Create 'access-list' for use with 'line vty' (Not Scored) .............................................. 36
1.2.5 Set 'access-class' for 'line vty' (Scored) ............................................................................ 38
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1.2.6 Set 'exec-timeout' to less than or equal to 10 minutes for 'line aux 0' (Scored)
..................................................................................................................................................................... 39
1.2.7 Set 'exec-timeout' to less than or equal to 10 minutes 'line console 0' (Scored)
..................................................................................................................................................................... 41
1.2.8 Set 'exec-timeout' less than or equal to 10 minutes 'line tty' (Scored) ............... 43
1.2.9 Set 'exec-timeout' to less than or equal to 10 minutes 'line vty' (Scored) ......... 45
1.2.10 Set 'transport input none' for 'line aux 0' (Scored)................................................... 47
1.3 Banner Rules ....................................................................................................................................... 48
1.3.1 Set the 'banner-text' for 'banner exec' (Scored) ........................................................... 49
1.3.2 Set the 'banner-text' for 'banner login' (Scored) .......................................................... 51
1.3.3 Set the 'banner-text' for 'banner motd' (Scored) ......................................................... 53
1.4 Password Rules .................................................................................................................................. 55
1.4.1 Set 'password' for 'enable secret' (Scored) .................................................................... 56
1.4.2 Enable 'service password-encryption' (Scored) ........................................................... 58
1.4.3 Set 'username secret' for all local users (Scored) ........................................................ 60
1.5 SNMP Rules.......................................................................................................................................... 62
1.5.1 Set 'no snmp-server' to disable SNMP when unused (Scored) ............................... 63
1.5.2 Unset 'private' for 'snmp-server community' (Scored) ............................................. 64
1.5.3 Unset 'public' for 'snmp-server community' (Scored) ............................................... 65
1.5.4 Do not set 'RW' for any 'snmp-server community' (Scored) ................................... 66
1.5.5 Set the ACL for each 'snmp-server community' (Scored) ......................................... 67
1.5.6 Create an 'access-list' for use with SNMP (Scored) ..................................................... 69
1.5.7 Set 'snmp-server host' when using SNMP (Scored) .................................................... 70
1.5.8 Set 'snmp-server enable traps snmp' (Scored) ............................................................. 71
1.5.9 Set 'priv' for each 'snmp-server group' using SNMPv3 (Scored) ........................... 72
1.5.10 Require 'aes 128' as minimum for 'snmp-server user' when using SNMPv3
(Scored) ................................................................................................................................................... 73
2 Control Plane ............................................................................................................................................... 74
2.1 Global Service Rules ......................................................................................................................... 74
2.1.1.1.1 Set the 'hostname' (Scored) ........................................................................................... 75
2.1.1.1.2 Set the 'ip domain name' (Scored) .............................................................................. 76
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2.1.1.1.3 Set 'modulus' to greater than or equal to 2048 for 'crypto key generate rsa'
(Not Scored) ........................................................................................................................................... 77
2.1.1.1.4 Set 'seconds' for 'ip ssh timeout' (Scored) ............................................................... 78
2.1.1.1.5 Set maximum value for 'ip ssh authentication-retries' (Scored) .................... 79
2.1.1.2 Set version 2 for 'ip ssh version' (Scored) ................................................................... 80
2.1.2 Set 'no cdp run' (Scored)........................................................................................................ 82
2.1.3 Set 'no ip bootp server' (Scored) ........................................................................................ 83
2.1.4 Set 'no service dhcp' (Scored) .............................................................................................. 84
2.1.5 Set 'no ip identd' (Scored) ..................................................................................................... 86
2.1.6 Set 'service tcp-keepalives-in' (Scored) ........................................................................... 87
2.1.7 Set 'service tcp-keepalives-out' (Scored) ........................................................................ 89
2.1.8 Set 'no service pad' (Scored) ................................................................................................ 91
2.2 Logging Rules ...................................................................................................................................... 92
2.2.1 Set 'logging on' (Scored) ........................................................................................................ 93
2.2.2 Set 'buffer size' for 'logging buffered' (Scored) ............................................................. 94
2.2.3 Set 'logging console critical' (Scored) ............................................................................... 95
2.2.4 Set IP address for 'logging host' (Scored) ....................................................................... 96
2.2.5 Set 'logging trap informational' (Scored) ........................................................................ 98
2.2.6 Set 'service timestamps debug datetime' (Scored) ..................................................... 99
2.2.7 Set 'logging source interface' (Scored) ........................................................................... 101
2.3 NTP Rules ........................................................................................................................................... 102
2.3.1.1 Set 'ntp authenticate' (Scored) ...................................................................................... 103
2.3.1.2 Set 'ntp authentication-key' (Scored) ......................................................................... 104
2.3.1.3 Set the 'ntp trusted-key' (Scored) ................................................................................. 105
2.3.1.4 Set 'key' for each 'ntp server' (Scored) ....................................................................... 106
2.3.2 Set 'ip address' for 'ntp server' (Scored) ....................................................................... 107
2.4 Loopback Rules ................................................................................................................................ 108
2.4.1 Create a single 'interface loopback' (Scored)............................................................... 109
2.4.2 Set AAA 'source-interface' (Scored) ................................................................................ 111
2.4.3 Set 'ntp source' to Loopback Interface (Scored)......................................................... 112
2.4.4 Set 'ip tftp source-interface' to the Loopback Interface (Scored) ........................ 113
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3 Data Plane ................................................................................................................................................... 114
3.1 Routing Rules .................................................................................................................................... 114
3.1.1 Set 'no ip source-route' (Scored) ...................................................................................... 115
3.1.2 Set 'no ip proxy-arp' (Scored) ............................................................................................ 116
3.1.3 Set 'no interface tunnel' (Scored) ..................................................................................... 118
3.1.4 Set 'ip verify unicast source reachable-via' (Scored) ................................................ 119
3.2 Border Router Filtering ................................................................................................................ 120
3.2.1 Set 'ip access-list extended' to Forbid Private Source Addresses from External
Networks (Not Scored) .................................................................................................................... 121
3.2.2 Set inbound 'ip access-group' on the External Interface (Not Scored) .............. 123
3.3 Neighbor Authentication .............................................................................................................. 124
3.3.1.1 Set 'key chain' (Scored) ..................................................................................................... 125
3.3.1.2 Set 'key' (Scored) ................................................................................................................. 126
3.3.1.3 Set 'key-string' (Scored) ................................................................................................... 127
3.3.1.4 Set 'address-family ipv4 autonomous-system' (Scored) ..................................... 128
3.3.1.5 Set 'af-interface default' (Scored) ................................................................................. 129
3.3.1.6 Set 'authentication key-chain' (Scored) ..................................................................... 130
3.3.1.7 Set 'authentication mode md5' (Scored) ................................................................... 132
3.3.1.8 Set 'ip authentication key-chain eigrp' (Scored) ..................................................... 134
3.3.1.9 Set 'ip authentication mode eigrp' (Scored) ............................................................. 135
3.3.2.1 Set 'authentication message-digest' for OSPF area (Scored) ............................. 137
3.3.2.2 Set 'ip ospf message-digest-key md5' (Scored) ....................................................... 138
3.3.3.1 Set 'key chain' (Scored) ..................................................................................................... 140
3.3.3.2 Set 'key' (Scored) ................................................................................................................. 141
3.3.3.3 Set 'key-string' (Scored) ................................................................................................... 142
3.3.3.4 Set 'ip rip authentication key-chain' (Scored) ......................................................... 143
3.3.3.5 Set 'ip rip authentication mode' to 'md5' (Scored) ................................................ 144
3.3.4.1 Set 'neighbor password' (Scored) ................................................................................. 146
Appendix: Change History ............................................................................................................................ 150
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Overview
This document, Security Configuration Benchmark for Cisco IOS, provides prescriptive
guidance for establishing a secure configuration posture for Cisco Router running Cisco IOS
version 15.0M. This guide was tested against Cisco IOS IP Advanced IP Services v15.0.1 as
installed by c880data-universalk9-mz.150-1.M4.bin. To obtain the latest version of this
guide, please visit http://benchmarks.cisecurity.org. If you have questions, comments, or
have identified ways to improve this guide, please write us at [email protected].
Intended Audience
This benchmark is intended for system and application administrators, security specialists,
auditors, help desk, and platform deployment personnel who plan to develop, deploy,
assess, or secure solutions that incorporate Cisco IOS on a Cisco routing and switching
platforms.
Consensus Guidance
This benchmark was created using a consensus review process comprised subject matter
experts. Consensus participants provide perspective from a diverse set of backgrounds
including consulting, software development, audit and compliance, security research,
operations, government, and legal.
Each CIS benchmark undergoes two phases of consensus review. The first phase occurs
during initial benchmark development. During this phase, subject matter experts convene
to discuss, create, and test working drafts of the benchmark. This discussion occurs until
consensus has been reached on benchmark recommendations. The second phase begins
after the benchmark has been published. During this phase, all feedback provided by the
Internet community is reviewed by the consensus team for incorporation in the
benchmark. If you are interested in participating in the consensus process, please visit
https://community.cisecurity.org.
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Typographical Conventions
The following typographical conventions are used throughout this guide:
Convention
Meaning
Stylized Monospace font
Used for blocks of code, command, and script examples.
Text should be interpreted exactly as presented.
Monospace font
Used for inline code, commands, or examples. Text should
be interpreted exactly as presented.
<italic font in brackets>
Italic texts set in angle brackets denote a variable
requiring substitution for a real value.
Italic font
Used to denote the title of a book, article, or other
publication.
Note
Additional information or caveats
Scoring Information
A scoring status indicates whether compliance with the given recommendation impacts the
assessed target's benchmark score. The following scoring statuses are used in this
benchmark:
Scored
Failure to comply with "Scored" recommendations will decrease the final benchmark score.
Compliance with "Scored" recommendations will increase the final benchmark score.
Not Scored
Failure to comply with "Not Scored" recommendations will not decrease the final
benchmark score. Compliance with "Not Scored" recommendations will not increase the
final benchmark score.
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Profile Definitions
The following configuration profiles are defined by this Benchmark:

Level 1
Items in this profile intend to:
o
o
o

be practical and prudent;
provide a clear security benefit; and
not inhibit the utility of the technology beyond acceptable means.
Level 2
This profile extends the "Level 1" profile. Items in this profile exhibit one or more of
the following characteristics:
o
o
o
are intended for environments or use cases where security is paramount.
acts as defense in depth measure.
may negatively inhibit the utility or performance of the technology.
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Acknowledgements
This benchmark exemplifies the great things a community of users, vendors, and subject matter
experts can accomplish through consensus collaboration. The CIS community thanks the entire
consensus team with special recognition to the following individuals who contributed greatly to
the creation of this guide:
Contributor
Justin Opatrny
Jason Nehrboss
Michael Hamelin
Craig Anteman
Jason Braun
Brian Sak
David McMillan
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Recommendations
1 Management Plane
Services, settings and data streams related to setting up and examining the static
configuration of the firewall, and the authentication and authorization of firewall
administrators. Examples of management plane services include: administrative device
access (telnet, ssh, http, and https), SNMP, and security protocols like RADIUS and
TACACS+.
1.1 Local Authentication, Authorization and Accounting (AAA)
Rules
Rules in the Local authentication, authorization and accounting (AAA) configuration class
enforce device access control; provide a mechanism for tracking configuration changes, and
enforcing security policy.
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1.1.1 Enable 'aaa new-model' (Scored)
Profile Applicability:
 Level 1
Description:
This command enables the AAA access control system.
Rationale:
Authentication, authorization and accounting (AAA) services provide an authoritative
source for managing and monitoring access for devices. Centralizing control improves
consistency of access control, the services that may be accessed once authenticated and
accountability by tracking services accessed. Additionally, centralizing access control
simplifies and reduces administrative costs of account provisioning and de-provisioning,
especially when managing a large number of devices.
Audit:
Perform the following to determine if AAA services are enabled:
hostname#show running-config | incl aaa new-model
If the result includes a "no", the feature is not enabled.
Remediation:
Globally enable authentication, authorization and accounting (AAA) using the new-model
command.
hostname(config)#aaa new-model
Impact:
Implementing Cisco AAA is significantly disruptive as former access methods are
immediately disabled. Therefore, before implementing Cisco AAA, the organization should
carefully review and plan their authentication criteria (logins & passwords, challenges &
responses, and token technologies), authorization methods, and accounting requirements.
Default Value:
AAA is not enabled.
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References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/a1/sec-cr-a2.html#GUIDE05C2E00-C01E-4053-9D12-EC37C7E8EEC5
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1.1.2 Enable 'aaa authentication login' (Scored)
Profile Applicability:
 Level 1
Description:
Sets authentication, authorization and accounting (AAA) authentication at login.
Rationale:
Using AAA authentication for interactive management access to the device provides
consistent, centralized control of your network. The default under AAA (local or network)
is to require users to log in using a valid user name and password. This rule applies for
both local and network AAA. Fallback mode should also be enabled to allow emergency
access to the router or switch in the event that the AAA server was unreachable, by
utilizing the LOCAL keyword after the AAA server-tag.
Audit:
Perform the following to determine if AAA authentication for login is enabled:
hostname#show run | incl aaa authentication login
If a result does not return, the feature is not enabled.
Remediation:
Configure AAA authentication method(s) for login authentication.
hostname(config)#aaa authentication login {default | aaa_list_name} [passwd-expiry]
method1 [method2]
Impact:
Implementing Cisco AAA is significantly disruptive as former access methods are
immediately disabled. Therefore, before implementing Cisco AAA, the organization should
carefully review and plan their authentication methods such as logins and passwords,
challenges and responses, and which token technologies will be used.
Default Value:
AAA authentication at login is disabled.
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References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/a1/sec-cr-a1.html#GUID3DB1CC8A-4A98-400B-A906-C42F265C7EA2
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1.1.3 Enable 'aaa authentication enable default' (Scored)
Profile Applicability:
 Level 1
Description:
Authenticates users who access privileged EXEC mode when they use the enable command.
Rationale:
Using AAA authentication for interactive management access to the device provides
consistent, centralized control of your network. The default under AAA (local or network)
is to require users to log in using a valid user name and password. This rule applies for
both local and network AAA.
Audit:
Perform the following to determine if AAA authentication enable mode is enabled:
hostname#show running-config | incl aaa authentication enable
If a result does not return, the feature is not enabled
Remediation:
Configure AAA authentication method(s) for enable authentication.
hostname(config)#aaa authentication enable default {method1} enable
Impact:
Enabling Cisco AAA 'authentication enable' mode is significantly disruptive as former
access methods are immediately disabled. Therefore, before enabling 'aaa authentication
enable default' mode, the organization should plan and implement authentication logins
and passwords, challenges and responses, and token technologies.
Default Value:
By default, fallback to the local database is disabled.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/a1/sec-cr-a1.html#GUID4171D649-2973-4707-95F3-9D96971893D0
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1.1.4 Set 'login authentication for 'line con 0' (Scored)
Profile Applicability:
 Level 1
Description:
Authenticates users who access the router or switch using the serial console port.
Rationale:
Using AAA authentication for interactive management access to the device provides
consistent, centralized control of your network. The default under AAA (local or network)
is to require users to log in using a valid user name and password. This rule applies for
both local and network AAA.
Audit:
Perform the following to determine if AAA authentication for line login is enabled:
If the command does not return a result for each management access method, the feature is
not enabled
hostname#sh run | sec line | incl login authentication
Remediation:
Configure management lines to require login using the default or a named AAA
authentication list. This configuration must be set individually for all line types.
hostname(config)#line console 0
hostname(config-line)#login authentication {default | aaa_list_name}
Impact:
Enabling Cisco AAA 'line login' is significantly disruptive as former access methods are
immediately disabled. Therefore, before enabling Cisco AAA 'line login', the organization
should plan and implement authentication logins and passwords, challenges and
responses, and token technologies.
Default Value:
Login authentication is not enabled.
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Uses the default set with aaa authentication login.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/d1/sec-crk1.html#GUID-297BDF33-4841-441C-83F3-4DA51C3C7284
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1.1.5 Set 'login authentication for 'line tty' (Scored)
Profile Applicability:
 Level 1
Description:
Authenticates users who access the router or switch using the TTY port.
Rationale:
Using AAA authentication for interactive management access to the device provides
consistent, centralized control of your network. The default under AAA (local or network)
is to require users to log in using a valid user name and password. This rule applies for
both local and network AAA.
Audit:
Perform the following to determine if AAA authentication for line login is enabled:
If the command does not return a result for each management access method, the feature is
not enabled
hostname#sh run | sec line | incl login authentication
Remediation:
Configure management lines to require login using the default or a named AAA
authentication list. This configuration must be set individually for all line types.
hostname(config)#line tty {line-number} [ending-line-number]
hostname(config-line)#login authentication {default | aaa_list_name}
Impact:
Enabling Cisco AAA 'login authentication for line TTY' is significantly disruptive as former
access methods are immediately disabled. Therefore, before enabling Cisco AAA 'login
authentication for line TTY', the organization should plan and implement authentication
logins and passwords, challenges and responses, and token technologies.
Default Value:
Login authentication is not enabled.
Uses the default set with aaa authentication login.
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References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/d1/sec-crk1.html#GUID-297BDF33-4841-441C-83F3-4DA51C3C7284
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1.1.6 Set 'login authentication for 'line vty' (Scored)
Profile Applicability:
 Level 1
Description:
Authenticates users who access the router or switch remotely through the VTY port.
Rationale:
Using AAA authentication for interactive management access to the device provides
consistent, centralized control of your network. The default under AAA (local or network)
is to require users to log in using a valid user name and password. This rule applies for
both local and network AAA.
Audit:
Perform the following to determine if AAA authentication for line login is enabled:
If the command does not return a result for each management access method, the feature is
not enabled
hostname#sh run | sec line | incl login authentication
Remediation:
Configure management lines to require login using the default or a named AAA
authentication list. This configuration must be set individually for all line types.
hostname(config)#line vty {line-number} [ending-line-number]
hostname(config-line)#login authentication {default | aaa_list_name}
Impact:
Enabling Cisco AAA 'login authentication for line VTY' is significantly disruptive as former
access methods are immediately disabled. Therefore, before enabling Cisco AAA 'login
authentication for line VTY', the organization should plan and implement authentication
logins and passwords, challenges and responses, and token technologies.
Default Value:
Login authentication is not enabled.
Uses the default set with aaa authentication login.
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References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/d1/sec-crk1.html#GUID-297BDF33-4841-441C-83F3-4DA51C3C7284
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1.1.7 Set 'aaa accounting' to log all privileged use commands using
'commands 15' (Scored)
Profile Applicability:
 Level 2
Description:
Runs accounting for all commands at the specified privilege level.
Rationale:
Authentication, authorization and accounting (AAA) systems provide an authoritative
source for managing and monitoring access for devices. Centralizing control improves
consistency of access control, the services that may be accessed once authenticated and
accountability by tracking services accessed. Additionally, centralizing access control
simplifies and reduces administrative costs of account provisioning and de-provisioning,
especially when managing a large number of devices. AAA Accounting provides a
management and audit trail for user and administrative sessions through RADIUS or
TACACS+.
Audit:
Perform the following to determine if aaa accounting for commands is required:
Verify a command string result returns
hostname#sh run | incl aaa accounting commands
Remediation:
Configure AAA accounting for commands.
hostname(config)#aaa accounting commands 15 {default | list-name | guarantee-first}
{start-stop | stop-only | none} {radius | group group-name}
Impact:
Enabling 'aaa accounting' for privileged commands records and sends activity to the
accounting servers and enables organizations to monitor and analyze privileged activity.
Default Value:
AAA accounting is disabled.
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1.1.8 Set 'aaa accounting connection' (Scored)
Profile Applicability:
 Level 2
Description:
Provides information about all outbound connections made from the network access
server.
Rationale:
Authentication, authorization and accounting (AAA) systems provide an authoritative
source for managing and monitoring access for devices. Centralizing control improves
consistency of access control, the services that may be accessed once authenticated and
accountability by tracking services accessed. Additionally, centralizing access control
simplifies and reduces administrative costs of account provisioning and de-provisioning,
especially when managing a large number of devices. AAA Accounting provides a
management and audit trail for user and administrative sessions through RADIUS and
TACACS+.
Audit:
Perform the following to determine if aaa accounting for connection is required:
Verify a command string result returns
hostname#sh run | incl aaa accounting connection
Remediation:
Configure AAA accounting for connections.
hostname(config)#aaa accounting connection {default | list-name | guarantee-first}
{start-stop | stop-only | none} {radius | group group-name}
Impact:
Implementing aaa accounting connection creates accounting records about connections
from the network access server. Organizations should regular monitor these connection
records for exceptions, remediate issues, and report findings regularly.
Default Value:
AAA accounting is not enabled.
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References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/a1/sec-cr-a1.html#GUID0520BCEF-89FB-4505-A5DF-D7F1389F1BBA
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1.1.9 Set 'aaa accounting exec' (Scored)
Profile Applicability:
 Level 2
Description:
Runs accounting for the EXEC shell session.
Rationale:
Authentication, authorization and accounting (AAA) systems provide an authoritative
source for managing and monitoring access for devices. Centralizing control improves
consistency of access control, the services that may be accessed once authenticated and
accountability by tracking services accessed. Additionally, centralizing access control
simplifies and reduces administrative costs of account provisioning and de-provisioning,
especially when managing a large number of devices. AAA Accounting provides a
management and audit trail for user and administrative sessions through RADIUS and
TACACS+.
Audit:
Perform the following to determine if aaa accounting for EXEC shell session is required:
Verify a command string result returns
hostname#sh run | incl aaa accounting exec
Remediation:
Configure AAA accounting for EXEC shell session.
hostname(config)#aaa accounting exec {default | list-name | guarantee-first}
{start-stop | stop-only | none} {radius | group group-name}
Impact:
Enabling aaa accounting exec creates accounting records for the EXEC terminal sessions on
the network access server. These records include start and stop times, usernames, and date
information. Organizations should regularly monitor these records for exceptions,
remediate issues, and report findings.
Default Value:
AAA accounting is not enabled.
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References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/a1/sec-cr-a1.html#GUID0520BCEF-89FB-4505-A5DF-D7F1389F1BBA
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1.1.10 Set 'aaa accounting network' (Scored)
Profile Applicability:
 Level 2
Description:
Runs accounting for all network-related service requests.
Rationale:
Authentication, authorization and accounting (AAA) systems provide an authoritative
source for managing and monitoring access for devices. Centralizing control improves
consistency of access control, the services that may be accessed once authenticated and
accountability by tracking services accessed. Additionally, centralizing access control
simplifies and reduces administrative costs of account provisioning and de-provisioning,
especially when managing a large number of devices. AAA Accounting provides a
management and audit trail for user and administrative sessions through RADIUS and
TACACS+.
Audit:
Perform the following to determine if aaa accounting for connection is required:
Verify a command string result returns
hostname#sh run | incl aaa accounting network
Remediation:
Configure AAA accounting for connections.
hostname(config)#aaa accounting network {default | list-name | guarantee-first}
{start-stop | stop-only | none} {radius | group group-name}
Impact:
Implementing aaa accounting network creates accounting records for a method list
including ARA, PPP, SLIP, and NCPs sessions. Organizations should regular monitor these
records for exceptions, remediate issues, and report findings.
Default Value:
AAA accounting is not enabled.
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References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/a1/sec-cr-a1.html#GUID0520BCEF-89FB-4505-A5DF-D7F1389F1BBA
29 | P a g e
1.1.11 Set 'aaa accounting system' (Scored)
Profile Applicability:
 Level 2
Description:
Performs accounting for all system-level events not associated with users, such as reloads.
Rationale:
Authentication, authorization and accounting (AAA) systems provide an authoritative
source for managing and monitoring access for devices. Centralizing control improves
consistency of access control, the services that may be accessed once authenticated and
accountability by tracking services accessed. Additionally, centralizing access control
simplifies and reduces administrative costs of account provisioning and de-provisioning,
especially when managing a large number of devices. AAA Accounting provides a
management and audit trail for user and administrative sessions through RADIUS and
TACACS+.
Audit:
Perform the following to determine if aaa accounting system is required:
Verify a command string result returns
hostname#sh run | incl aaa accounting system
Remediation:
Configure AAA accounting system.
hostname(config)#aaa accounting system {default | list-name | guarantee-first}
{start-stop | stop-only | none} {radius | group group-name}
Impact:
Enabling aaa accounting system creates accounting records for all system-level events.
Organizations should regular monitor these records for exceptions, remediate issues, and
report findings regularly.
Default Value:
AAA accounting is not enabled.
30 | P a g e
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/a1/sec-cr-a1.html#GUID0520BCEF-89FB-4505-A5DF-D7F1389F1BBA
1.2 Access Rules
Rules in the access class enforce controls for device administrative connections.
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1.2.1 Set 'privilege 1' for local users (Scored)
Profile Applicability:
 Level 1
Description:
Sets the privilege level for the user.
Rationale:
Default device configuration does not require strong user authentication potentially
enabling unfettered access to an attacker that is able to reach the device. Creating a local
account with privilege level 1 permissions only allows the local user to access the device
with EXEC-level permissions and will be unable to modify the device without using the
enable password. In addition, require the use of an encrypted password as well (see
Section 1.1.4.4 - Require Encrypted User Passwords).
Audit:
Perform the following to determine if a user with an encrypted password is enabled:
Verify all username results return "privilege 1"
hostname#show run | incl privilege
Remediation:
Set the local user to privilege level 1.
hostname(config)#username <LOCAL_USERNAME> privilege 1
Impact:
Organizations should create policies requiring all local accounts with 'privilege level 1' with
encrypted passwords to reduce the risk of unauthorized access. Default configuration
settings do not provide strong user authentication to the device.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/s1/sec-cr-t2z.html#GUID-34B3E43E-0F79-40E8-82B6-A4B5F1AFF1AD
32 | P a g e
1.2.2 Set 'transport input ssh' for 'line vty' connections (Scored)
Profile Applicability:
 Level 1
Description:
Selects the Secure Shell (SSH) protocol.
Rationale:
Configuring VTY access control restricts remote access to only those authorized to manage
the device and prevents unauthorized users from accessing the system.
Audit:
Perform the following to determine if SSH is the only transport method for incoming VTY
logins:
The result should show only "ssh" for "transport input"
hostname#sh run | sec vty
Remediation:
Apply SSH to transport input on all VTY management lines
hostname(config)#line vty <line-number> <ending-line-number>
hostname(config-line)#transport input ssh
Impact:
To reduce risk of unauthorized access, organizations should require all VTY management
line protocols to be limited to ssh.
References:
1. http://www.cisco.com/en/US/docs/ios/termserv/command/reference/tsv_s1.htm
l#wp1069219
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1.2.3 Set 'no exec' for 'line aux 0' (Scored)
Profile Applicability:
 Level 1
Description:
The 'no exec' command restricts a line to outgoing connections only.
Rationale:
Unused ports should be disabled, if not required, since they provide a potential access path
for attackers. Some devices include both an auxiliary and console port that can be used to
locally connect to and configure the device. The console port is normally the primary port
used to configure the device; even when remote, backup administration is required via
console server or Keyboard, Video, Mouse (KVM) hardware. The auxiliary port is primarily
used for dial-up administration via an external modem; instead, use other available
methods.
Audit:
Perform the following to determine if the EXEC process for the aux port is disabled:
Verify no exec
hostname#sh run | sec aux
Verify you see the following "no exec"
hostname#sh line aux 0 | incl exec
Remediation:
Disable the EXEC process on the auxiliary port.
hostname(config)#line aux 0
hostname(config-line)#no exec
Impact:
Organizations can reduce the risk of unauthorized access by disabling the 'aux' port with
the 'no exec' command. Conversely, not restricting access through the 'aux' port increases
the risk of remote unauthorized access.
References:
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1. http://www.cisco.com/en/US/docs/iosxml/ios/fundamentals/command/D_through_E.html#GUID-429A2B8C-FC26-49C494C4-0FD99C32EC34
35 | P a g e
1.2.4 Create 'access-list' for use with 'line vty' (Not Scored)
Profile Applicability:
 Level 1
Description:
Access lists control the transmission of packets on an interface, control Virtual Terminal
Line (VTY) access, and restrict the contents of routing updates. The Cisco IOS software
stops checking the extended access list after a match occurs.
Rationale:
VTY ACLs control what addresses may attempt to log in to the router. Configuring VTY lines
to use an ACL, restricts the sources where a user can manage the device. You should limit
the specific host(s) and or network(s) authorized to connect to and configure the device,
via an approved protocol, to those individuals or systems authorized to administer the
device. For example, you could limit access to specific hosts, so that only network managers
can configure the devices only by using specific network management workstations. Make
sure you configure all VTY lines to use the same ACL.
Audit:
Perform the following to determine if the ACL is created:
Verify the appropriate access-list definitions
hostname#sh ip access-list <vty_acl_number>
Remediation:
Configure the VTY ACL that will be used to restrict management access to the device.
hostname(config)#access-list <vty_acl_number> permit tcp <vty_acl_block_with_mask> any
hostname(config)#access-list <vty_acl_number> permit tcp host <vty_acl_host> any
hostname(config)#deny ip any any log
Impact:
Organizations can reduce the risk of unauthorized access by implementing access-lists for
all VTY lines. Conversely, using VTY lines without access-lists increases the risk of
unauthorized access.
References:
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1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/a1/sec-cr-a2.html#GUID9EA733A3-1788-4882-B8C3-AB0A2949120C
37 | P a g e
1.2.5 Set 'access-class' for 'line vty' (Scored)
Profile Applicability:
 Level 1
Description:
The 'access-class' setting restricts incoming and outgoing connections between a particular
vty (into a Cisco device) and the networking devices associated with addresses in an access
list.
Rationale:
Restricting the type of network devices, associated with the addresses on the access-list,
further restricts remote access to those devices authorized to manage the device and
reduces the risk of unauthorized access.
Audit:
Perform the following to determine if the ACL is set:
Verify you see the access-class defined
hostname#sh run | sec vty <line-number> <ending-line-number>
Remediation:
Configure remote management access control restrictions for all VTY lines.
hostname(config)#line vty <line-number> <ending-line-number>
hostname(config-line)# access-class <vty_acl_number> in
Impact:
Applying 'access class' to line VTY further restricts remote access to only those devices
authorized to manage the device and reduces the risk of unauthorized access. Conversely,
using VTY lines with 'access class' restrictions increases the risks of unauthorized access.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/a1/sec-cr-a2.html#GUIDFB9BC58A-F00A-442A-8028-1E9E260E54D3
38 | P a g e
1.2.6 Set 'exec-timeout' to less than or equal to 10 minutes for 'line aux
0' (Scored)
Profile Applicability:
 Level 1
Description:
If no input is detected during the interval, the EXEC facility resumes the current connection.
If no connections exist, the EXEC facility returns the terminal to the idle state and
disconnects the incoming session.
Rationale:
This prevents unauthorized users from misusing abandoned sessions. For example, if the
network administrator leaves for the day and leaves a computer open with an enabled
login session accessible. There is a trade-off here between security (shorter timeouts) and
usability (longer timeouts). Review your local policies and operational needs to determine
the best timeout value. In most cases, this should be no more than 10 minutes.
Audit:
Perform the following to determine if the timeout is configured:
Verify you return a result
NOTE: If you set an exec-timeout of 10 minutes, this will not show up in the configuration
hostname#sh run | sec line aux 0
Remediation:
Configure device timeout (10 minutes or less) to disconnect sessions after a fixed idle time.
hostname(config)#line aux 0
hostname(config-line)#exec-timeout <timeout_in_minutes> <timeout_in_seconds>
Impact:
Organizations should prevent unauthorized use of unattended or abandoned sessions by an
automated control. Enabling 'exec-timeout' with an appropriate length of minutes or
seconds prevents unauthorized access of abandoned sessions.
References:
39 | P a g e
1. http://www.cisco.com/en/US/docs/iosxml/ios/fundamentals/command/D_through_E.html#GUID-76805E6F-9E89-4457A9DC-5944C8FE5419
40 | P a g e
1.2.7 Set 'exec-timeout' to less than or equal to 10 minutes 'line console
0' (Scored)
Profile Applicability:
 Level 1
Description:
If no input is detected during the interval, the EXEC facility resumes the current connection.
If no connections exist, the EXEC facility returns the terminal to the idle state and
disconnects the incoming session.
Rationale:
This prevents unauthorized users from misusing abandoned sessions. For example, if the
network administrator leaves for the day and leaves a computer open with an enabled
login session accessible. There is a trade-off here between security (shorter timeouts) and
usability (longer timeouts). Review your local policies and operational needs to determine
the best timeout value. In most cases, this should be no more than 10 minutes.
Audit:
Perform the following to determine if the timeout is configured:
Verify you return a result
NOTE: If you set an exec-timeout of 10 minutes, this will not show up in the configuration
hostname#sh run | sec line con 0
Remediation:
Configure device timeout (10 minutes or less) to disconnect sessions after a fixed idle time.
hostname(config)#line con 0
hostname(config-line)#exec-timeout <timeout_in_minutes> <timeout_in_seconds>
Impact:
Organizations should prevent unauthorized use of unattended or abandoned sessions by an
automated control. Enabling 'exec-timeout' with an appropriate length reduces the risk of
unauthorized access of abandoned sessions.
References:
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1. http://www.cisco.com/en/US/docs/iosxml/ios/fundamentals/command/D_through_E.html#GUID-76805E6F-9E89-4457A9DC-5944C8FE5419
42 | P a g e
1.2.8 Set 'exec-timeout' less than or equal to 10 minutes 'line tty'
(Scored)
Profile Applicability:
 Level 1
Description:
If no input is detected during the interval, the EXEC facility resumes the current connection.
If no connections exist, the EXEC facility returns the terminal to the idle state and
disconnects the incoming session.
Rationale:
This prevents unauthorized users from misusing abandoned sessions. For example, if the
network administrator leaves for the day and leaves a computer open with an enabled
login session accessible. There is a trade-off here between security (shorter timeouts) and
usability (longer timeouts). Review your local policies and operational needs to determine
the best timeout value. In most cases, this should be no more than 10 minutes.
Audit:
Perform the following to determine if the timeout is configured:
Verify you return a result
NOTE: If you set an exec-timeout of 10 minutes, this will not show up in the configuration
hostname#sh line tty <tty_line_number> | begin Timeout
Remediation:
Configure device timeout (10 minutes or less) to disconnect sessions after a fixed idle time.
hostname(config)#line tty {line_number} [ending_line_number]
hostname(config-line)#exec-timeout <timeout_in_minutes> <timeout_in_seconds>
Impact:
Organizations should prevent unauthorized use of unattended or abandoned sessions by an
automated control. Enabling 'exec-timeout' with an appropriate length reduces the risks of
unauthorized access of abandoned sessions.
References:
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1. http://www.cisco.com/en/US/docs/iosxml/ios/fundamentals/command/D_through_E.html#GUID-76805E6F-9E89-4457A9DC-5944C8FE5419
44 | P a g e
1.2.9 Set 'exec-timeout' to less than or equal to 10 minutes 'line vty'
(Scored)
Profile Applicability:
 Level 1
Description:
If no input is detected during the interval, the EXEC facility resumes the current connection.
If no connections exist, the EXEC facility returns the terminal to the idle state and
disconnects the incoming session.
Rationale:
This prevents unauthorized users from misusing abandoned sessions. For example, if the
network administrator leaves for the day and leaves a computer open with an enabled
login session accessible. There is a trade-off here between security (shorter timeouts) and
usability (longer timeouts). Review your local policies and operational needs to determine
the best timeout value. In most cases, this should be no more than 10 minutes.
Audit:
Perform the following to determine if the timeout is configured:
Verify you return a result
NOTE: If you set an exec-timeout of 10 minutes, this will not show up in the configuration
hostname#sh line vty <tty_line_number> | begin Timeout
Remediation:
Configure device timeout (10 minutes or less) to disconnect sessions after a fixed idle time.
hostname(config)#line vty {line_number} [ending_line_number]
hostname(config-line)#exec-timeout <timeout_in_minutes> <timeout_in_seconds>
Impact:
Organizations should prevent unauthorized use of unattended or abandoned sessions by an
automated control. Enabling 'exec-timeout' with an appropriate length of minutes or
seconds prevents unauthorized access of abandoned sessions.
References:
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1. http://www.cisco.com/en/US/docs/iosxml/ios/fundamentals/command/D_through_E.html#GUID-76805E6F-9E89-4457A9DC-5944C8FE5419
46 | P a g e
1.2.10 Set 'transport input none' for 'line aux 0' (Scored)
Profile Applicability:
 Level 1
Description:
When you want to allow only an outgoing connection on a line, use the no exec command.
Rationale:
Unused ports should be disabled, if not required, since they provide a potential access path
for attackers. Some devices include both an auxiliary and console port that can be used to
locally connect to and configure the device. The console port is normally the primary port
used to configure the device; even when remote, backup administration is required via
console server or Keyboard, Video, Mouse (KVM) hardware. The auxiliary port is primarily
used for dial-up administration via an external modem; instead, use other available
methods.
Audit:
Perform the following to determine if inbound connections for the aux port are disabled:
Verify you see the following "Allowed input transports are none
hostname#sh line aux 0 | incl input transports
Remediation:
Disable the inbound connections on the auxiliary port.
hostname(config)#line aux 0
hostname(config-line)#transport input none
Impact:
Organizations should prevent all unauthorized access of auxiliary ports by disabling all
protocols using the 'transport input none' command.
References:
1. http://www.cisco.com/en/US/docs/ios/termserv/command/reference/tsv_s1.htm
l#wp1069219
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1.3 Banner Rules
Rules in the banner class communicate legal rights to users.
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1.3.1 Set the 'banner-text' for 'banner exec' (Scored)
Profile Applicability:
 Level 1
Description:
This command specifies a message to be displayed when an EXEC process is created (a line
is activated, or an incoming connection is made to a vty). Follow this command with one or
more blank spaces and a delimiting character of your choice. Then enter one or more lines
of text, terminating the message with the second occurrence of the delimiting character.
When a user connects to a router, the message-of-the-day (MOTD) banner appears first,
followed by the login banner and prompts. After the user logs in to the router, the EXEC
banner or incoming banner will be displayed, depending on the type of connection. For a
reverse Telnet login, the incoming banner will be displayed. For all other connections, the
router will display the EXEC banner.
Rationale:
"Network banners are electronic messages that provide notice of legal rights to users of
computer networks. From a legal standpoint, banners have four primary functions.




First, banners may be used to generate consent to real-time monitoring under Title
III.
Second, banners may be used to generate consent to the retrieval of stored files and
records pursuant to ECPA.
Third, in the case of government networks, banners may eliminate any Fourth
Amendment "reasonable expectation of privacy" that government employees or
other users might otherwise retain in their use of the government's network under
O'Connor v. Ortega, 480 U.S. 709 (1987).
Fourth, in the case of a non-government network, banners may establish a system
administrator's "common authority" to consent to a law enforcement search
pursuant to United States v. Matlock, 415 U.S. 164 (1974)." (US Department of
Justice APPENDIX A: Sample Network Banner Language)
Audit:
Perform the following to determine if the exec banner is set:
hostname#sh running-config | beg banner exec
If the command does not return a result, the banner is not enabled
Remediation:
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Configure the EXEC banner presented to a user when accessing the devices enable prompt.
hostname(config)#banner exec c
Enter TEXT message. End with the character 'c'.
<banner-text>
c
Impact:
Organizations provide appropriate legal notice(s) and warning(s) to persons accessing
their networks by using a 'banner-text' for the banner exec command.
Default Value:
No banner is set by default
References:
1. http://www.cisco.com/en/US/docs/iosxml/ios/fundamentals/command/A_through_B.html#GUID-0DEF5B57-A7D9-4912861F-E837C82A3881
50 | P a g e
1.3.2 Set the 'banner-text' for 'banner login' (Scored)
Profile Applicability:
 Level 1
Description:
Follow the banner login command with one or more blank spaces and a delimiting
character of your choice. Then enter one or more lines of text, terminating the message
with the second occurrence of the delimiting character.
When a user connects to the router, the message-of-the-day (MOTD) banner (if configured)
appears first, followed by the login banner and prompts. After the user successfully logs in
to the router, the EXEC banner or incoming banner will be displayed, depending on the
type of connection. For a reverse Telnet login, the incoming banner will be displayed. For
all other connections, the router will display the EXEC banner.
Rationale:
"Network banners are electronic messages that provide notice of legal rights to users of
computer networks. From a legal standpoint, banners have four primary functions.




First, banners may be used to generate consent to real-time monitoring under Title
III.
Second, banners may be used to generate consent to the retrieval of stored files and
records pursuant to ECPA.
Third, in the case of government networks, banners may eliminate any Fourth
Amendment "reasonable expectation of privacy" that government employees or
other users might otherwise retain in their use of the government's network under
O'Connor v. Ortega, 480 U.S. 709 (1987).
Fourth, in the case of a non-government network, banners may establish a system
administrator's "common authority" to consent to a law enforcement search
pursuant to United States v. Matlock, 415 U.S. 164 (1974)." (US Department of
Justice APPENDIX A: Sample Network Banner Language)
Audit:
Perform the following to determine if the login banner is set:
hostname#show running-config | beg banner login
If the command does not return a result, the banner is not enabled.
Remediation:
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Configure the device so a login banner presented to a user attempting to access the device.
hostname(config)#banner login c
Enter TEXT message. End with the character 'c'.
<banner-text>
c
Impact:
Organizations provide appropriate legal notice(s) and warning(s) to persons accessing
their networks by using a 'banner-text' for the banner login command.
Default Value:
No banner is set by default
References:
1. http://www.cisco.com/en/US/docs/iosxml/ios/fundamentals/command/A_through_B.html#GUID-FF0B6890-85B8-4B6A90DD-1B7140C5D22F
52 | P a g e
1.3.3 Set the 'banner-text' for 'banner motd' (Scored)
Profile Applicability:
 Level 1
Description:
This MOTD banner is displayed to all terminals connected and is useful for sending
messages that affect all users (such as impending system shutdowns). Use the no execbanner or no motd-banner command to disable the MOTD banner on a line. The no execbanner command also disables the EXEC banner on the line.
When a user connects to the router, the MOTD banner appears before the login prompt.
After the user logs in to the router, the EXEC banner or incoming banner will be displayed,
depending on the type of connection. For a reverse Telnet login, the incoming banner will
be displayed. For all other connections, the router will display the EXEC banner.
Rationale:
"Network banners are electronic messages that provide notice of legal rights to users of
computer networks. From a legal standpoint, banners have four primary functions.




First, banners may be used to generate consent to real-time monitoring under Title
III.
Second, banners may be used to generate consent to the retrieval of stored files and
records pursuant to ECPA.
Third, in the case of government networks, banners may eliminate any Fourth
Amendment "reasonable expectation of privacy" that government employees or
other users might otherwise retain in their use of the government's network under
O'Connor v. Ortega, 480 U.S. 709 (1987).
Fourth, in the case of a non-government network, banners may establish a system
administrator's "common authority" to consent to a law enforcement search
pursuant to United States v. Matlock, 415 U.S. 164 (1974)." (US Department of
Justice APPENDIX A: Sample Network Banner Language)
Audit:
Perform the following to determine if the login banner is set:
hostname#sh running-config | beg banner motd
If the command does not return a result, the banner is not enabled.
Remediation:
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Configure the message of the day (MOTD) banner presented when a user first connects to
the device.
hostname(config)#banner motd c
Enter TEXT message. End with the character 'c'.
<banner-text>
c
Impact:
Organizations provide appropriate legal notice(s) and warning(s) to persons accessing
their networks by using a 'banner-text' for the banner motd command.
Default Value:
No banner is set by default
References:
1. http://www.cisco.com/en/US/docs/iosxml/ios/fundamentals/command/A_through_B.html#GUID-7416C789-9561-44FCBB2A-D8D8AFFB77DD
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1.4 Password Rules
Rules in the password class enforce secure, local device authentication credentials.
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1.4.1 Set 'password' for 'enable secret' (Scored)
Profile Applicability:
 Level 1
Description:
Use the enable secret command to provide an additional layer of security over the enable
password. The enable secret command provides better security by storing the enable
secret password using a nonreversible cryptographic function. The added layer of security
encryption provides is useful in environments where the password crosses the network or
is stored on a TFTP server.
Rationale:
Requiring the enable secret setting protects privileged EXEC mode. By default, a strong
password is not required, a user can just press the Enter key at the Password prompt to
start privileged mode. The enable password command causes the device to enforce use of a
password to access privileged mode. Enable secrets use a one-way cryptographic hash
(MD5). This is preferred to Level 7 enable passwords that use a weak, well-known, and
easily reversible encryption algorithm.
Audit:
Perform the following to determine enable secret is set:
If the command does not return a result, the enable password is not set.
hostname#sh run | incl enable secret
Remediation:
Configure a strong, enable secret password.
hostname(config)#enable secret <ENABLE_SECRET_PASSWORD>
Impact:
Organizations should protect privileged EXEC mode through policies requiring the
'enabling secret' setting, which enforces a one-way cryptographic hash (MD5).
Default Value:
No enable secret password setup by default
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References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/d1/sec-cre1.html#GUID-944C261C-7D4A-49E1-AA8F-C754750BDE47
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1.4.2 Enable 'service password-encryption' (Scored)
Profile Applicability:
 Level 1
Description:
When password encryption is enabled, the encrypted form of the passwords is displayed
when a more system:running-config command is entered.
Rationale:
This requires passwords to be encrypted in the configuration file to prevent unauthorized
users from learning the passwords just by reading the configuration. When not enabled,
many of the device's passwords will be rendered in plain text in the configuration file. This
service ensures passwords are rendered as encrypted strings preventing an attacker from
easily determining the configured value.
Audit:
Perform the following to determine if a user with an encrypted password is enabled:
Ensure a result that matches the command return
hostname#sh run | incl service password-encryption
Remediation:
Enable password encryption service to protect sensitive access passwords in the device
configuration.
hostname(config)#service password-encryption
Impact:
Organizations implementing 'service password-encryption' reduce the risk of unauthorized
users learning clear text passwords to Cisco IOS configuration files. However, the algorithm
used is not designed to withstand serious analysis and should be treated like clear-text.
Default Value:
Service password encryption is not set by default
References:
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1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/s1/sec-cr-s1.html#GUIDCC0E305A-604E-4A74-8A1A-975556CE5871
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1.4.3 Set 'username secret' for all local users (Scored)
Profile Applicability:
 Level 1
Description:
Use the username secret command to configure a username and MD5-encrypted user
password. MD5 encryption is a strong encryption method that is not retrievable; thus, you
cannot use MD5 encryption with protocols that require clear-text passwords, such as
Challenge Handshake Authentication Protocol (CHAP).
The username secret command provides an additional layer of security over the username
password. It also provides better security by encrypting the password using non reversible
MD5 encryption and storing the encrypted text. The added layer of MD5 encryption is
useful in environments in which the password crosses the network or is stored on a TFTP
server.
Rationale:
Default device configuration does not require strong user authentication potentially
enabling unfettered access to an attacker that is able to reach the device. Creating a local
account with an encrypted password enforces login authentication and provides a fallback
authentication mechanism for configuration in a named method list in a situation where
centralized authentication, authorization, and accounting services are unavailable.
Audit:
Perform the following to determine if a user with an encrypted password is enabled:
If a result does not return with secret, the feature is not enabled
hostname#show run | incl username
Remediation:
Create a local user with an encrypted, complex (not easily guessed) password.
hostname(config)#username <LOCAL_USERNAME> secret <LOCAL_PASSWORD>
Impact:
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Organizations implementing 'username secret' across their enterprise reduce the risk of
unauthorized users gaining access to Cisco IOS devices by applying a MD5 hash and
encrypting user passwords.
Default Value:
No passwords are set by default
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/s1/sec-cr-t2z.html#GUID-5071E577-5249-4EA1-9226-BD426BEAD5B9
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1.5 SNMP Rules
Simple Network Management Protocol (SNMP) provides a standards-based interface to
manage and monitor network devices. This section provides guidance on the secure
configuration of SNMP parameters.
The recommendations in this Section apply to Organizations using SNMP. Organizations
using SNMP should review and implement the recommendations in this section.
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1.5.1 Set 'no snmp-server' to disable SNMP when unused (Scored)
Profile Applicability:
 Level 1
Description:
If not in use, disable simple network management protocol (SNMP), read and write access.
Rationale:
SNMP read access allows remote monitoring and management of the device.
Audit:
Verify the result reads "SNMP agent not enabled"
hostname#show snmp community
Remediation:
Disable SNMP read and write access if not in used to monitor and/or manage device.
hostname(config)#no snmp-server
Impact:
Organizations not using SNMP should require all SNMP services to be disabled by running
the 'no snmp-server' command.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/snmp/command/nm-snmp-crbook.html
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1.5.2 Unset 'private' for 'snmp-server community' (Scored)
Profile Applicability:
 Level 1
Description:
An SNMP community string permits read-only access to all objects.
Rationale:
The default community string "private" is well known. Using easy to guess, well known
community string poses a threat that an attacker can effortlessly gain unauthorized access
to the device.
Audit:
Perform the following to determine if the public community string is enabled:
Ensure private does not show as a result
hostname# show snmp community
Remediation:
Disable the default SNMP community string "private"
hostname(config)#no snmp-server community {private}
Impact:
To reduce the risk of unauthorized access, Organizations should disable default, easy to
guess, settings such as the 'private' setting for snmp-server community.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/snmp/command/nm-snmp-crs2.html#GUID-2F3F13E4-EE81-4590-871D-6AE1043473DE
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1.5.3 Unset 'public' for 'snmp-server community' (Scored)
Profile Applicability:
 Level 1
Description:
An SNMP community string permits read-only access to all objects.
Rationale:
The default community string "public" is well known. Using easy to guess, well known
community string poses a threat that an attacker can effortlessly gain unauthorized access
to the device.
Audit:
Perform the following to determine if the public community string is enabled:
Ensure public does not show as a result
hostname# show snmp community
Remediation:
Disable the default SNMP community string "public"
hostname(config)#no snmp-server community {public}
Impact:
To reduce the risk of unauthorized access, Organizations should disable default, easy to
guess, settings such as the 'public' setting for snmp-server community.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/snmp/command/nm-snmp-crs2.html#GUID-2F3F13E4-EE81-4590-871D-6AE1043473DE
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1.5.4 Do not set 'RW' for any 'snmp-server community' (Scored)
Profile Applicability:
 Level 1
Description:
Specifies read-write access. Authorized management stations can both retrieve and modify
MIB objects.
Rationale:
Enabling SNMP read-write enables remote management of the device. Unless absolutely
necessary, do not allow simple network management protocol (SNMP) write access.
Audit:
Perform the following to determine if a read/write community string is enabled:
Verify the result does not show a community string with a "RW"
hostname#show run | incl snmp-server community
Remediation:
Disable SNMP write access.
hostname(config)#no snmp-server community {write_community_string}
Impact:
To reduce the risk of unauthorized access, Organizations should disable the SNMP 'write'
access for snmp-server community.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/snmp/command/nm-snmp-crs2.html#GUID-2F3F13E4-EE81-4590-871D-6AE1043473DE
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1.5.5 Set the ACL for each 'snmp-server community' (Scored)
Profile Applicability:
 Level 1
Description:
This feature specifies a list of IP addresses that are allowed to use the community string to
gain access to the SNMP agent.
Rationale:
If ACLs are not applied, then anyone with a valid SNMP community string can potentially
monitor and manage the router. An ACL should be defined and applied for all SNMP access
to limit access to a small number of authorized management stations segmented in a
trusted management zone. If possible, use SNMPv3 which uses authentication,
authorization, and data privatization (encryption).
Audit:
Perform the following to determine if an ACL is enabled:
Verify the result shows a number after the community string
hostname#show run | incl snmp-server community
Remediation:
Configure authorized SNMP community string and restrict access to authorized
management systems.
hostname(config)#snmp-server community <community_string> ro {snmp_access-list_number
|
snmp_access-list_name}
Impact:
To reduce the risk of unauthorized access, Organizations should enable access control lists
for all snmp-server communities and restrict the access to appropriate trusted
management zones. If possible, implement SNMPv3 to apply authentication, authorization,
and data privatization (encryption) for additional benefits to the organization.
Default Value:
No ACL is set for SNMP
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References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/snmp/command/nm-snmp-crs2.html#GUID-2F3F13E4-EE81-4590-871D-6AE1043473DE
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1.5.6 Create an 'access-list' for use with SNMP (Scored)
Profile Applicability:
 Level 1
Description:
You can use access lists to control the transmission of packets on an interface, control
Simple Network Management Protocol (SNMP) access, and restrict the contents of routing
updates. The Cisco IOS software stops checking the extended access list after a match
occurs.
Rationale:
SNMP ACLs control what addresses are authorized to manage and monitor the device via
SNMP. If ACLs are not applied, then anyone with a valid SNMP community string may
monitor and manage the router. An ACL should be defined and applied for all SNMP
community strings to limit access to a small number of authorized management stations
segmented in a trusted management zone.
Audit:
Perform the following to determine if the ACL is created:
Verify you the appropriate access-list definitions
hostname#sh ip access-list <snmp_acl_number>
Remediation:
Configure SNMP ACL for restricting access to the device from authorized management
stations segmented in a trusted management zone.
hostname(config)#access-list <snmp_acl_number> permit <snmp_access-list>
hostname(config)#access-list deny any log
Default Value:
SNMP does not use an access list.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/a1/sec-cr-a2.html#GUID9EA733A3-1788-4882-B8C3-AB0A2949120C
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1.5.7 Set 'snmp-server host' when using SNMP (Scored)
Profile Applicability:
 Level 1
Description:
SNMP notifications can be sent as traps to authorized management systems.
Rationale:
If SNMP is enabled for device management and device alerts are required, then ensure the
device is configured to submit traps only to authorize management systems.
Audit:
Perform the following to determine if SNMP traps are enabled:
If the command returns configuration values, then SNMP is enabled.
hostname#show run snmp-server
Remediation:
Configure authorized SNMP trap community string and restrict sending messages to
authorized management systems.
hostname(config)#snmp-server host {ip_address} {trap_community_string} snmp
Impact:
Organizations using SNMP should restrict sending SNMP messages only to explicitly named
systems to reduce unauthorized access.
Default Value:
A recipient is not specified to receive notifications.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/snmp/command/nm-snmp-crs5.html#GUID-D84B2AB5-6485-4A23-8C26-73E50F73EE61
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1.5.8 Set 'snmp-server enable traps snmp' (Scored)
Profile Applicability:
 Level 1
Description:
SNMP notifications can be sent as traps to authorized management systems.
Rationale:
SNMP has the ability to submit traps .
Audit:
Perform the following to determine if SNMP traps are enabled:
If the command returns configuration values, then SNMP is enabled.
hostname#show run snmp-server
Remediation:
Enable SNMP traps.
hostname(config)#snmp-server enable traps snmp authentication linkup linkdown
coldstart
Impact:
Organizations using SNMP should restrict trap types only to explicitly named traps to
reduce unintended traffic. Enabling SNMP traps without specifying trap type will enable all
SNMP trap types.
Default Value:
SNMP notifications are disabled.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/snmp/command/nm-snmp-crs3.html#GUID-EB3EB677-A355-42C6-A139-85BA30810C54
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1.5.9 Set 'priv' for each 'snmp-server group' using SNMPv3 (Scored)
Profile Applicability:
 Level 2
Description:
Specifies authentication of a packet with encryption when using SNMPv3
Rationale:
SNMPv3 provides much improved security over previous versions by offering options for
Authentication and Encryption of messages.
When configuring a user for SNMPv3 you have the option of using a range of encryption
schemes, or no encryption at all, to protect messages in transit. AES128 is the minimum
strength encryption method that should be deployed.
Audit:
Verify the result show the appropriate group name and security model
hostname#show snmp groups
Remediation:
For each SNMPv3 group created on your router add privacy options by issuing the
following command...
hostname(config)#snmp-server group {group_name} v3 priv
Impact:
Organizations using SNMP can significantly reduce the risks of unauthorized access by
using the 'snmp-server group v3 priv' setting to encrypt messages in transit.
Default Value:
No SNMP server groups are configured.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/snmp/command/nm-snmp-crs5.html#GUID-56E87D02-C56F-4E2D-A5C8-617E31740C3F
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1.5.10 Require 'aes 128' as minimum for 'snmp-server user' when using
SNMPv3 (Scored)
Profile Applicability:
 Level 2
Description:
Specify the use of a minimum of 128-bit AES algorithm for encryption when using SNMPv3.
Rationale:
SNMPv3 provides much improved security over previous versions by offering options for
Authentication and Encryption of messages.
When configuring a user for SNMPv3 you have the option of using a range of encryption
schemes, or no encryption at all, to protect messages in transit. AES128 is the minimum
strength encryption method that should be deployed.
Audit:
Verify the result show the appropriate user name and security settings
hostname#show snmp user
Remediation:
For each SNMPv3 user created on your router add privacy options by issuing the following
command.
hostname(config)#snmp-server user {user_name} {group_name} v3 encrypted auth sha
{auth_password} priv aes 128 {priv_password} {acl_name_or_number}
Impact:
Organizations using SNMP can significantly reduce the risks of unauthorized access by
using the 'snmp-server user' setting with appropriate authentication and privacy protocols
to encrypt messages in transit.
Default Value:
SNMP username as not set by default.
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References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/snmp/command/nm-snmp-crs5.html#GUID-4EED4031-E723-4B84-9BBF-610C3CF60E31
2 Control Plane
The control plane covers monitoring, route table updates, and generally the dynamic
operation of the router. Services, settings, and data streams that support and document the
operation, traffic handling, and dynamic status of the router. Examples of control plane
services include: logging (e.g. Syslog), routing protocols, status protocols like CDP and
HSRP, network topology protocols like STP, and traffic security control protocols like IKE.
Network control protocols like ICMP, NTP, ARP, and IGMP directed to or sent by the router
itself also fall into this area.
2.1 Global Service Rules
Rules in the global service class enforce server and service controls that protect against
attacks or expose the device to exploitation.
2.1.1 Setup SSH
Ensure use of SSH remote console sessions to Cisco routers.
2.1.1.1 Configure Prerequisites for the SSH Service
[This space intentionally left blank]
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2.1.1.1.1 Set the 'hostname' (Scored)
Profile Applicability:
 Level 1
Description:
The hostname is used in prompts and default configuration filenames.
Rationale:
The domain name is prerequisite for setting up SSH.
Audit:
Perform the following to determine if the local time zone is configured:
Verify the result shows the summer-time recurrence is configured properly.
hostname#sh run | incl hostname
Remediation:
Configure an appropriate host name for the router.
hostname(config)#hostname {router_name}
Impact:
Organizations should plan the enterprise network and identify an appropriate host name
for each router.
Default Value:
The default hostname is Router.
References:
1. http://www.cisco.com/en/US/docs/iosxml/ios/fundamentals/command/F_through_K.html#GUID-F3349988-EC16-484ABE81-4C40110E6625
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2.1.1.1.2 Set the 'ip domain name' (Scored)
Profile Applicability:
 Level 1
Description:
Define a default domain name that the Cisco IOS software uses to complete unqualified
hostnames
Rationale:
The domain name is a prerequisite for setting up SSH.
Audit:
Perform the following to determine if the domain name is configured:
Verify the domain name is configured properly.
hostname#sh run | incl domain name
Remediation:
Configure an appropriate domain name for the router.
hostname (config)#ip domain name {domain-name}
Impact:
Organizations should plan the enterprise network and identify an appropriate domain
name for the router.
Default Value:
No domain is set.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/ipaddr/command/ipaddri3.html#GUID-A706D62B-9170-45CE-A2C2-7B2052BE2CAB
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2.1.1.1.3 Set 'modulus' to greater than or equal to 2048 for 'crypto key
generate rsa' (Not Scored)
Profile Applicability:
 Level 1
Description:
Use this command to generate RSA key pairs for your Cisco device.
RSA keys are generated in pairs--one public RSA key and one private RSA key.
Rationale:
An RSA key pair is a prerequisite for setting up SSH and should be at least 2048 bits.
NOTE: IOS does NOT display the modulus bit value in the Audit Procedure.
Audit:
Perform the following to determine if the RSA key pair is configured:
hostname#sh crypto key mypubkey rsa
Remediation:
Generate an RSA key pair for the router.
hostname(config)#crypto key generate rsa general-keys modulus 2048
Impact:
Organizations should plan and implement enterprise network cryptography and generate
an appropriate RSA key pairs, such as 'modulus', greater than or equal to 2048.
Default Value:
RSA key pairs do not exist.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/a1/sec-cr-c4.html#GUID2AECF701-D54A-404E-9614-D3AAB049BC13
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2.1.1.1.4 Set 'seconds' for 'ip ssh timeout' (Scored)
Profile Applicability:
 Level 1
Description:
The time interval that the router waits for the SSH client to respond before disconnecting
an uncompleted login attempt.
Rationale:
This reduces the risk of an administrator leaving an authenticated session logged in for an
extended period of time.
Audit:
Perform the following to determine if the SSH timeout is configured:
Verify the timeout is configured properly.
hostname#sh ip ssh
Remediation:
Configure the SSH timeout
hostname(config)#ip ssh timeout [60]
Impact:
Organizations should implement a security policy requiring minimum timeout settings for
all network administrators and enforce the policy through the 'ip ssh timeout' command.
Default Value:
SSH in not enabled by default.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/d1/sec-cr-i3.html#GUID5BAC7A2B-0A25-400F-AEE9-C22AE08513C6
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2.1.1.1.5 Set maximum value for 'ip ssh authentication-retries' (Scored)
Profile Applicability:
 Level 1
Description:
The number of retries before the SSH login session disconnects.
Rationale:
This limits the number of times an unauthorized user can attempt a password without
having to establish a new SSH login attempt. This reduces the potential for success during
online brute force attacks by limiting the number of login attempts per SSH connection.
Audit:
Perform the following to determine if SSH authentication retries is configured:
Verify the authentication retries is configured properly.
hostname#sh ip ssh
Remediation:
Configure the SSH timeout:
hostname(config)#ip ssh authentication-retries [3]
Impact:
Organizations should implement a security policy limiting the number of authentication
attempts for network administrators and enforce the policy through the 'ip ssh
authentication-retries' command.
Default Value:
SSH is not enabled by default. When set, the default value is 3.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/d1/sec-cr-i3.html#GUID5BAC7A2B-0A25-400F-AEE9-C22AE08513C6
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2.1.1.2 Set version 2 for 'ip ssh version' (Scored)
Profile Applicability:
 Level 1
Description:
Specify the version of Secure Shell (SSH) to be run on a router
Rationale:
SSH Version 1 has been subject to a number of serious vulnerabilities and is no longer
considered to be a secure protocol, resulting in the adoption of SSH Version 2 as an Internet
Standard in 2006.
Cisco routers support both versions, but due to the weakness of SSH Version 1 only the
later standard should be used.
Audit:
Perform the following to determine if SSH version 2 is configured:
Verify that SSH version 2 is configured properly.
hostname#sh ip ssh
Remediation:
Configure the router to use SSH version 2
hostname(config)#ip ssh version 2
Impact:
To reduce the risk of unauthorized access, organizations should implement a security
policy to review their current protocols to ensure the most secure protocol versions are in
use.
Default Value:
SSH is not enabled by default. When enabled, SSH operates in compatibility mode
(versions 1 and 2 supported).
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References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/d1/sec-cr-i3.html#GUID170AECF1-4B5B-462A-8CC8-999DEDC45C21
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2.1.2 Set 'no cdp run' (Scored)
Profile Applicability:
 Level 1
Description:
Disable Cisco Discovery Protocol (CDP) service at device level.
Rationale:
The Cisco Discovery Protocol is a proprietary protocol that Cisco devices use to identify
each other on a LAN segment. It is useful only in network monitoring and troubleshooting
situations but is considered a security risk because of the amount of information provided
from queries. In addition, there have been published denial-of-service (DoS) attacks that
use CDP. CDP should be completely disabled unless necessary.
Audit:
Perform the following to determine if CDP is enabled:
Verify the result shows "CDP is not enabled"
hostname#show cdp
Remediation:
Disable Cisco Discovery Protocol (CDP) service globally.
hostname(config)#no cdp run
Impact:
To reduce the risk of unauthorized access, organizations should implement a security
policy restricting network protocols and explicitly require disabling all insecure or
unnecessary protocols.
Default Value:
Enabled on all platforms except the Cisco 10000 Series Edge Services Router
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/cdp/command/cdp-cra1.html#GUID-E006FAC8-417E-4C3F-B732-4D47B0447750
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2.1.3 Set 'no ip bootp server' (Scored)
Profile Applicability:
 Level 1
Description:
Disable the Bootstrap Protocol (BOOTP) service on your routing device.
Rationale:
BootP allows a router to issue IP addresses. This should be disabled unless there is a
specific requirement.
Audit:
Perform the following to determine if bootp is enabled:
Verify a "no ip bootp server" result returns
hostname#show run | incl bootp
Remediation:
Disable the bootp server.
hostname(config)#no ip bootp server
Impact:
To reduce the risk of unauthorized access, organizations should implement a security
policy restricting network protocols and explicitly require disabling all insecure or
unnecessary protocols such as 'ip bootp server'.
Default Value:
Enabled
References:
1. Cisco IOS software receives Cisco Discovery Protocol information
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2.1.4 Set 'no service dhcp' (Scored)
Profile Applicability:
 Level 1
Description:
Disable the Dynamic Host Configuration Protocol (DHCP) server and relay agent features
on your router.
Rationale:
The DHCP server supplies automatic configuration parameters, such as dynamic IP
address, to requesting systems. A dedicated server located in a secured management zone
should be used to provide DHCP services instead. Attackers can potentially be used for
denial-of-service (DoS) attacks.
Audit:
Perform the following to determine if the DHCP service is enabled:
Verify no result returns
hostname#show run | incl dhcp
Remediation:
Disable the DHCP server.
hostname(config)#no service dhcp
Impact:
To reduce the risk of unauthorized access, organizations should implement a security
policy restricting network protocols and explicitly require disabling all insecure or
unnecessary protocols such as the Dynamic Host Configuration Protocol (DHCP).
Default Value:
Enabled by default, but also requires a DHCP pool to be set to activate the DHCP server.
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References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/ipaddr/command/ipaddrr1.html#GUID-1516B259-AA28-4839-B968-8DDBF0B382F6
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2.1.5 Set 'no ip identd' (Scored)
Profile Applicability:
 Level 1
Description:
Disable the identification (identd) server.
Rationale:
Identification protocol enables identifying a user's transmission control protocol (TCP)
session. This information disclosure could potentially provide an attacker with information
about users.
Audit:
Perform the following to determine if identd is enabled:
Verify no result returns
hostname#show run | incl identd
Remediation:
Disable the ident server.
hostname(config)#no ip identd
Impact:
To reduce the risk of unauthorized access, organizations should implement a security
policy restricting network protocols and explicitly require disabling all insecure or
unnecessary protocols such as the identification protocol (identd).
Default Value:
Enabled by default
References:
1. http://www.cisco.com/en/US/docs/solutions/Enterprise/Security/Baseline_Securi
ty/sec_chap4.html#wp1056539
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2.1.6 Set 'service tcp-keepalives-in' (Scored)
Profile Applicability:
 Level 1
Description:
Generate keepalive packets on idle incoming network connections.
Rationale:
Stale connections use resources and could potentially be hijacked to gain illegitimate
access. The TCP keepalives-in service generates keepalive packets on idle incoming
network connections (initiated by remote host). This service allows the device to detect
when the remote host fails and drop the session. If enabled, keepalives are sent once per
minute on idle connections. The connection is closed within five minutes if no keepalives
are received or immediately if the host replies with a reset packet.
Audit:
Perform the following to determine if the feature is enabled:
Verify a command string result returns
hostname#show run | incl service tcp
Remediation:
Enable TCP keepalives-in service:
hostname(config)#service tcp-keepalives-in
Impact:
To reduce the risk of unauthorized access, organizations should implement a security
policy restricting how long to allow terminated sessions and enforce this policy through the
use of 'tcp-keepalives-in' command.
Default Value:
Disabled by default.
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References:
1. http://www.cisco.com/en/US/docs/iosxml/ios/fundamentals/command/R_through_setup.html#GUID-1489ABA3-24284A64-B252-296A035DB85E
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2.1.7 Set 'service tcp-keepalives-out' (Scored)
Profile Applicability:
 Level 1
Description:
Generate keepalive packets on idle outgoing network connections.
Rationale:
Stale connections use resources and could potentially be hijacked to gain illegitimate
access. The TCP keepalives-in service generates keepalive packets on idle incoming
network connections (initiated by remote host). This service allows the device to detect
when the remote host fails and drop the session. If enabled, keepalives are sent once per
minute on idle connections. The closes connection is closed within five minutes if no
keepalives are received or immediately if the host replies with a reset packet.
Audit:
Perform the following to determine if the feature is enabled:
Verify a command string result returns
hostname#show run | incl service tcp
Remediation:
Enable TCP keepalives-out service:
hostname(config)#service tcp-keepalives-out
Impact:
To reduce the risk of unauthorized access, organizations should implement a security
policy restricting how long to allow terminated sessions and enforce this policy through the
use of 'tcp-keepalives-out' command.
Default Value:
Disabled by default.
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References:
1. http://www.cisco.com/en/US/docs/iosxml/ios/fundamentals/command/R_through_setup.html#GUID-9321ECDC-62844BF6-BA4A-9CEEF5F993E5
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2.1.8 Set 'no service pad' (Scored)
Profile Applicability:
 Level 1
Description:
Disable X.25 Packet Assembler/Disassembler (PAD) service.
Rationale:
If the PAD service is not necessary, disable the service to prevent intruders from accessing
the X.25 PAD command set on the router.
Audit:
Perform the following to determine if the feature is disabled:
Verify no result returns
hostname#show run | incl service pad
Remediation:
Disable the PAD service.
hostname(config)#no service pad
Impact:
To reduce the risk of unauthorized access, organizations should implement a security
policy restricting unnecessary services such as the 'PAD' service.
Default Value:
Enabled by default.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/wan/command/wans1.html#GUID-C5497B77-3FD4-4D2F-AB08-1317D5F5473B
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2.2 Logging Rules
Rules in the logging class enforce controls that provide a record of system activity and
events.
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2.2.1 Set 'logging on' (Scored)
Profile Applicability:
 Level 1
Description:
Enable logging of system messages.
Rationale:
Logging provides a chronological record of activities on the Cisco device and allows
monitoring of both operational and security related events.
Audit:
Perform the following to determine if the feature is enabled:
Verify no result returns
hostname#show run | incl logging on
Remediation:
Enable system logging.
hostname(config)#logging on
Impact:
Enabling the Cisco IOS 'logging on' command enforces the monitoring of technology risks
for the organizations' network devices.
Default Value:
Logging is not enabled/
References:
1. http://www.cisco.com/en/US/docs/ios/netmgmt/command/reference/nm_09.htm
l#wp1014324
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2.2.2 Set 'buffer size' for 'logging buffered' (Scored)
Profile Applicability:
 Level 1
Description:
Enable system message logging to a local buffer.
Rationale:
The device can copy and store log messages to an internal memory buffer. The buffered
data is available only from a router exec or enabled exec session. This form of logging is
useful for debugging and monitoring when logged in to a router.
Audit:
Perform the following to determine if the feature is enabled:
Verify a command string result returns
hostname#show run | incl logging buffered
Remediation:
Configure buffered logging (with minimum size). Recommended size is 64000.
hostname(config)#logging buffered [log_buffer_size]
Impact:
Data forensics is effective managing technology risks and an organization can enforce such
policies by enabling the 'logging buffered' command.
Default Value:
No logging buffer is set by default
References:
1. http://www.cisco.com/en/US/docs/ios/netmgmt/command/reference/nm_09.htm
l#wp1060051
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2.2.3 Set 'logging console critical' (Scored)
Profile Applicability:
 Level 1
Description:
Verify logging to device console is enabled and limited to a rational severity level to avoid
impacting system performance and management.
Rationale:
This configuration determines the severity of messages that will generate console
messages. Logging to console should be limited only to those messages required for
immediate troubleshooting while logged into the device. This form of logging is not
persistent; messages printed to the console are not stored by the router. Console logging is
handy for operators when they use the console.
Audit:
Perform the following to determine if the feature is enabled:
Verify a command string result returns
hostname#show run | incl logging console
Remediation:
Configure console logging level.
hostname(config)#logging console critical
Impact:
Logging critical messages at the console is important for an organization managing
technology risk. The 'logging console' command should capture appropriate severity
messages to be effective.
Default Value:
The default is to log all messages
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2.2.4 Set IP address for 'logging host' (Scored)
Profile Applicability:
 Level 1
Description:
Log system messages and debug output to a remote host.
Rationale:
Cisco routers can send their log messages to a Unix-style Syslog service. A syslog service
simply accepts messages and stores them in files or prints them according to a simple
configuration file. This form of logging is best because it can provide protected long-term
storage for logs (the devices internal logging buffer has limited capacity to store events.) In
addition, logging to an external system is highly recommended or required by most
security standards. If desired or required by policy, law and/or regulation, enable a second
syslog server for redundancy.
Audit:
Perform the following to determine if a syslog server is enabled:
Verify one or more IP address(es) returns
hostname#sh log | incl logging host
Remediation:
Designate one or more syslog servers by IP address.
hostname(config)#logging host syslog_server
Impact:
Logging is an important process for an organization managing technology risk. The 'logging
host' command sets the IP address of the logging host and enforces the logging process.
Default Value:
System logging messages are not sent to any remote host.
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References:
1. http://www.cisco.com/en/US/docs/ios/netmgmt/command/reference/nm_09.htm
l#wp1082864
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2.2.5 Set 'logging trap informational' (Scored)
Profile Applicability:
 Level 1
Description:
Limit messages logged to the syslog servers based on severity level informational.
Rationale:
This determines the severity of messages that will generate simple network management
protocol (SNMP) trap and or syslog messages. This setting should be set to either
"debugging" (7) or "informational" (6), but no lower.
Audit:
Perform the following to determine if a syslog server for SNMP traps is enabled:
Verify "level informational" returns
hostname#sh log | incl trap logging
Remediation:
Configure SNMP trap and syslog logging level.
hostname(config)#logging trap informational
Impact:
Logging is an important process for an organization managing technology risk. The 'logging
trap' command sets the severity of messages and enforces the logging process.
Default Value:
Disabled
References:
1. http://www.cisco.com/en/US/docs/ios/netmgmt/command/reference/nm_09.htm
l#wp1015177
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2.2.6 Set 'service timestamps debug datetime' (Scored)
Profile Applicability:
 Level 1
Description:
Configure the system to apply a time stamp to debugging messages or system logging
messages
Rationale:
Including timestamps in log messages allows correlating events and tracing network
attacks across multiple devices. Enabling service timestamp to mark the time log messages
were generated simplifies obtaining a holistic view of events enabling faster
troubleshooting of issues or attacks.
Audit:
Perform the following to determine if the additional detail is enabled:
Verify a command string result returns
hostname#sh run | incl service timestamps
Remediation:
Configure debug messages to include timestamps.
hostname(config)#service timestamps debug datetime {msec} show-timezone
Impact:
Logging is an important process for an organization managing technology risk and
establishing a timeline of events is critical. The 'service timestamps' command sets the date
and time on entries sent to the logging host and enforces the logging process.
Default Value:
Time stamps are applied to debug and logging messages.
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References:
1. http://www.cisco.com/en/US/docs/iosxml/ios/fundamentals/command/R_through_setup.html#GUID-DC110E59-D2944E3D-B67F-CCB06E607FC6
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2.2.7 Set 'logging source interface' (Scored)
Profile Applicability:
 Level 1
Description:
Specify the source IPv4 or IPv6 address of system logging packets
Rationale:
This is required so that the router sends log messages to the logging server from a
consistent IP address.
Audit:
Perform the following to determine if logging services are bound to a source interface:
Verify a command string result returns
hostname#sh run | incl logging source
Remediation:
Bind logging to the loopback interface.
hostname(config)#logging source-interface loopback {loopback_interface_number}
Impact:
Logging is an important process for an organization managing technology risk and
establishing a consistent source of messages for the logging host is critical. The 'logging
source interface loopback' command sets a consistent IP address to send messages to the
logging host and enforces the logging process.
Default Value:
The wildcard interface address is used.
References:
1. http://www.cisco.com/en/US/docs/ios/netmgmt/command/reference/nm_09.htm
l#wp1095099
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2.3 NTP Rules
Network Time Protocol allows administrators to set the system time on all of their
compatible systems from a single source, ensuring a consistent time stamp for logging and
authentication protocols. NTP is an internet standard, defined in RFC1305.
2.3.1 Require Encryption Keys for NTP
Encryption keys should be set for NTP Servers.
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2.3.1.1 Set 'ntp authenticate' (Scored)
Profile Applicability:
 Level 2
Description:
Enable NTP authentication.
Rationale:
Using authenticated NTP ensures the Cisco device only permits time updates from
authorized NTP servers.
Audit:
From the command prompt, execute the following commands:
hostname#show run | include ntp
Remediation:
Configure NTP authentication:
hostname(config)#ntp authenticate
Impact:
Organizations should establish three Network Time Protocol (NTP) hosts to set consistent
time across the enterprise. Enabling the 'ntp authenticate' command enforces
authentication between NTP hosts.
Default Value:
NTP authentication is not enabled.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/bsm/command/bsm-crn1.html#GUID-8BEBDAF4-6D03-4C3E-B8D6-6BCBC7D0F324
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2.3.1.2 Set 'ntp authentication-key' (Scored)
Profile Applicability:
 Level 2
Description:
Define an authentication key for Network Time Protocol (NTP).
Rationale:
Using an authentication key provides a higher degree of security as only authenticated NTP
servers will be able to update time for the Cisco device.
Audit:
From the command prompt, execute the following commands:
hostname#show run | include ntp authentication-key
Remediation:
Configure at the NTP key ring and encryption key using the following command
hostname(config)#ntp authentication-key {ntp_key_id} md5 {ntp_key}
Impact:
Organizations should establish three Network Time Protocol (NTP) hosts to set consistent
time across the enterprise. Enabling the 'ntp authentication-key' command enforces
encrypted authentication between NTP hosts.
Default Value:
No authentication key is defined for NTP.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/bsm/command/bsm-crn1.html#GUID-0435BFD1-D7D7-41D4-97AC-7731C11226BC
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2.3.1.3 Set the 'ntp trusted-key' (Scored)
Profile Applicability:
 Level 2
Description:
Ensure you authenticate the identity of a system to which Network Time Protocol (NTP)
will synchronize
Rationale:
This authentication function provides protection against accidentally synchronizing the
system to another system that is not trusted, because the other system must know the
correct authentication key.
Audit:
From the command prompt, execute the following commands:
hostname#show run | include ntp trusted-key
The above command should return any NTP server(s) configured with encryption keys.
This value should be the same as the total number of servers configured as tested in.
Remediation:
Configure the NTP trusted key using the following command
hostname(config)#ntp trusted-key {ntp_key_id}
Impact:
Organizations should establish three Network Time Protocol (NTP) hosts to set consistent
time across the enterprise. Enabling the 'ntp trusted-key' command enforces encrypted
authentication between NTP hosts.
Default Value:
Authentication of the identity of the system is disabled.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/bsm/command/bsm-crn1.html#GUID-89CA798D-0F12-4AE8-B382-DE10CBD261DB
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2.3.1.4 Set 'key' for each 'ntp server' (Scored)
Profile Applicability:
 Level 2
Description:
Specifies the authentication key for NTP.
Rationale:
This authentication feature provides protection against accidentally synchronizing the ntp
system to another system that is not trusted, because the other system must know the
correct authentication key.
Audit:
From the command prompt, execute the following commands:
hostname#show run | include ntp server
Remediation:
Configure each NTP Server to use a key ring using the following command.
hostname(config)#ntp server {ntp-server_ip_address}{key ntp_key_id}
Impact:
Organizations should establish three Network Time Protocol (NTP) hosts to set consistent
time across the enterprise. Enabling the 'ntp server key' command enforces encrypted
authentication between NTP hosts.
Default Value:
No NTP key is set by default
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2.3.2 Set 'ip address' for 'ntp server' (Scored)
Profile Applicability:
 Level 1
Description:
Use this command if you want to allow the system to synchronize the system software
clock with the specified NTP server.
Rationale:
To ensure that the time on your Cisco router is consistent with other devices in your
network, at least two (and preferably at least three) NTP Server/s external to the router
should be configured.
Ensure you also configure consistent timezone and daylight savings time setting for all
devices. For simplicity, the default of Coordinated Universal Time (UTC).
Audit:
From the command prompt, execute the following commands:
hostname#sh ntp associations
Remediation:
Configure at least one external NTP Server using the following commands
hostname(config)#ntp server {ip address}
Impact:
Organizations should establish three Network Time Protocol (NTP) hosts to set consistent
time across the enterprise. Enabling the 'ntp server ip address' enforces encrypted
authentication between NTP hosts.
Default Value:
No servers are configured by default.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/bsm/command/bsm-crn1.html#GUID-255145EB-D656-43F0-B361-D9CBCC794112
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2.4 Loopback Rules
When a router needs to initiate connections to remote hosts, for example for SYSLOG or
NTP, it will use the nearest interface for the packets source address. This can cause issues
due to the possible variation in source, potentially causing packets to be denied by
intervening firewalls or handled incorrectly by the receiving host.
To prevent these problems the router should be configured with a Loopback interface and
any services should be bound to this address.
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2.4.1 Create a single 'interface loopback' (Scored)
Profile Applicability:
 Level 2
Description:
Configure a single loopback interface.
Rationale:
Software-only loopback interface that emulates an interface that is always up. It is a virtual
interface supported on all platforms.
Alternate loopback addresses create a potential for abuse, mis-configuration, and
inconsistencies. Additional loopback interfaces must be documented and approved prior to
use by local security personnel.
Audit:
Perform the following to determine if a loopback interface is defined:
Verify an IP address returns for the defined loopback interface
hostname#sh ip int brief | incl Loopback
Remediation:
Define and configure one loopback interface.
hostname(config)#interface loopback <number>
hostname(config-if)#ip address <loopback_ip_address> <loopback_subnet_mask>
Impact:
Organizations should plan and establish 'loopback interfaces' for the enterprise network.
Loopback interfaces enable critical network information such as OSPF Router IDs and
provide termination points for routing protocol sessions.
Default Value:
There are no loopback interfaces defined by default.
References:
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1. http://www.cisco.com/en/US/docs/ios-xml/ios/interface/command/iri1.html#GUID-0D6BDFCD-3FBB-4D26-A274-C1221F8592DF
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2.4.2 Set AAA 'source-interface' (Scored)
Profile Applicability:
 Level 2
Description:
Force AAA to use the IP address of a specified interface for all outgoing AAA packets
Rationale:
This is required so that the AAA server (RADIUS or TACACS+) can easily identify routers
and authenticate requests by their IP address.
Audit:
Perform the following to determine if AAA services are bound to a source interface:
Verify a command string result returns
hostname#sh run | incl tacacs source | radius source
Remediation:
Bind AAA services to the loopback interface.
Hostname(config)#ip {tacacs|radius} source-interface loopback
{loopback_interface_number)
Impact:
Organizations should design and implement authentication, authorization, and accounting
(AAA) services for effective monitoring of enterprise network devices. Binding AAA
services to the source-interface loopback enables these services.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/d1/sec-cr-i2.html#GUID22E8B211-751F-48E0-9C76-58F0FE0AABA8
2. http://www.cisco.com/en/US/docs/ios-xml/ios/security/d1/sec-cr-i3.html#GUID54A00318-CF69-46FC-9ADC-313BFC436713
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2.4.3 Set 'ntp source' to Loopback Interface (Scored)
Profile Applicability:
 Level 2
Description:
Use a particular source address in Network Time Protocol (NTP) packets.
Rationale:
Set the source address to be used when sending NTP traffic. This may be required if the
NTP servers you peer with filter based on IP address.
Audit:
Perform the following to determine if NTP services are bound to a source interface:
Verify a command string result returns
hostname#sh run | incl ntp source
Remediation:
Bind the NTP service to the loopback interface.
hostname(config)#ntp source loopback {loopback_interface_number}
Impact:
Organizations should plan and implement network time protocol (NTP) services to
establish official time for all enterprise network devices. Setting 'ntp source loopback'
enforces the proper IP address for NTP services.
Default Value:
Source address is determined by the outgoing interface.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/bsm/command/bsm-crn1.html#GUID-DF29FBFB-E1C0-4E5C-9013-D4CE59CA0B88
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2.4.4 Set 'ip tftp source-interface' to the Loopback Interface (Scored)
Profile Applicability:
 Level 2
Description:
Specify the IP address of an interface as the source address for TFTP connections.
Rationale:
This is required so that the TFTP servers can easily identify routers and authenticate
requests by their IP address.
Audit:
Perform the following to determine if TFTP services are bound to a source interface:
Verify a command string result returns
hostname#sh run | incl tftp source-interface
Remediation:
Bind the TFTP client to the loopback interface.
hostname(config)#ip tftp source-interface loopback {loobpback_interface_number}
Impact:
Organizations should plan and implement trivial file transfer protocol (TFTP) services in
the enterprise by setting 'tftp source-interface loopback', which enables the TFTP servers
to identify routers and authenticate requests by IP address.
Default Value:
The address of the closest interface to the destination is selected as the source address.
References:
1. http://www.cisco.com/en/US/docs/iosxml/ios/fundamentals/command/F_through_K.html#GUID-9AA27050-A578-47CD9F1D-5A8E2B449209
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3 Data Plane
Services and settings related to the data passing through the router (as opposed to direct to
it). The data plane is for everything not in control or management planes. Settings on a
router concerned with the data plane include interface access lists, firewall functionality
(e.g. CBAC), NAT, and IPSec. Settings for traffic-affecting services like unicast RPF
verification and CAR/QoS also fall into this area.
3.1 Routing Rules
Unneeded services should be disabled.
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3.1.1 Set 'no ip source-route' (Scored)
Profile Applicability:
 Level 1
Description:
Disable the handling of IP datagrams with source routing header options.
Rationale:
Source routing is a feature of IP whereby individual packets can specify routes. This feature
is used in several kinds of attacks. Cisco routers normally accept and process source routes.
Unless a network depends on source routing, it should be disabled.
Audit:
Verify the command string result returns
hostname#sh run | incl ip source-route
Remediation:
Disable source routing.
hostname(config)#no ip source-route
Impact:
Organizations should plan and implement network policies to ensure unnecessary services
are explicitly disabled. The 'ip source-route' feature has been used in several attacks and
should be disabled.
Default Value:
Enabled by default
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/ipaddr/command/ipaddri4.html#GUID-C7F971DD-358F-4B43-9F3E-244F5D4A3A93
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3.1.2 Set 'no ip proxy-arp' (Scored)
Profile Applicability:
 Level 2
Description:
Disable proxy ARP on all interfaces.
Rationale:
Address Resolution Protocol (ARP) provides resolution between IP and MAC Addresses (or
other Network and Link Layer addresses on none IP networks) within a Layer 2 network.
Proxy ARP is a service where a device connected to one network (in this case the Cisco
router) answers ARP Requests which are addressed to a host on another network, replying
with its own MAC Address and forwarding the traffic on to the intended host.
Sometimes used for extending broadcast domains across WAN links, in most cases Proxy
ARP on enterprise networks is used to enable communication for hosts with misconfigured subnet masks, a situation which should no longer be a common problem. Proxy
ARP effectively breaks the LAN Security Perimeter, extending a network across multiple
Layer 2 segments. Using Proxy ARP can also allow other security controls such as PVLAN to
be bypassed.
Audit:
Verify the proxy ARP status
hostname#sh ip int {interface} | incl proxy-arp
Remediation:
Disable proxy ARP on all interfaces.
hostname(config)#interface {interface}
hostname(config-if)#no ip proxy-arp
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Impact:
Organizations should plan and implement network policies to ensure unnecessary services
are explicitly disabled. The 'ip proxy-arp' feature effectively breaks the LAN security
perimeter and should be disabled.
Default Value:
Enabled
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/ipaddr/command/ipaddri4.html#GUID-AEB7DDCB-7B3D-4036-ACF0-0A0250F3002E
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3.1.3 Set 'no interface tunnel' (Scored)
Profile Applicability:
 Level 2
Description:
Verify no tunnel interfaces are defined.
Rationale:
Tunnel interfaces should not exist in general. They can be used for malicious purposes. If
they are necessary, the network admin's should be well aware of them and their purpose.
Audit:
Verify no tunnel interfaces are defined
hostname#sh ip int brief | incl tunnel
Remediation:
Remove any tunnel interfaces.
hostname(config)#no interface tunnel {instance}
Impact:
Organizations should plan and implement enterprise network security policies that disable
insecure and unnecessary features that increase attack surfaces such as 'tunnel interfaces'.
Default Value:
No tunnel interfaces are defined
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/interface/command/iri1.html#GUID-0D6BDFCD-3FBB-4D26-A274-C1221F8592DF
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3.1.4 Set 'ip verify unicast source reachable-via' (Scored)
Profile Applicability:
 Level 2
Description:
Examines incoming packets to determine whether the source address is in the Forwarding
Information Base (FIB) and permits the packet only if the source is reachable through the
interface on which the packet was received (sometimes referred to as strict mode).
Rationale:
Enabled uRPF helps mitigate IP spoofing by ensuring only packet source IP addresses only
originate from expected interfaces. Configure unicast reverse-path forwarding (uRPF) on
all external or high risk interfaces.
Audit:
Verify uRPF is running on the appropriate interface(s)
hostname#sh ip int {interface} | incl verify source
Remediation:
Configure uRPF.
hostname(config)#interface {interface_name}
hostname(config-if)#ip verify unicast source reachable-via rx
Impact:
Organizations should plan and implement enterprise security policies that protect the
confidentiality, integrity, and availability of network devices. The 'unicast Reverse-Path
Forwarding' (uRPF) feature dynamically uses the router table to either accept or drop
packets when arriving on an interface.
Default Value:
Unicast RPF is disabled.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/d1/sec-cr-i3.html#GUID2ED313DB-3D3F-49D7-880A-047463632757
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3.2 Border Router Filtering
A border-filtering device connects "internal" networks such as desktop networks, DMZ
networks, etc., to "external" networks such as the Internet. If this group is chosen, then
ingress and egress filter rules will be required.
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3.2.1 Set 'ip access-list extended' to Forbid Private Source Addresses
from External Networks (Not Scored)
Profile Applicability:
 Level 2
Description:
This command places the router in access-list configuration mode, where you must define
the denied or permitted access conditions by using the deny and permit commands.
Rationale:
Configuring access controls can help prevent spoofing attacks. To reduce the effectiveness
of IP spoofing, configure access control to deny any traffic from the external network that
has a source address that should reside on the internal network. Include local host address
or any reserved private addresses (RFC 1918).
Ensure the permit rule(s) above the final deny rule only allow traffic according to your
organization's least privilege policy.
Audit:
Verify you have the appropriate access-list definitions
hostname#sh ip access-list {name | number}
Remediation:
Configure ACL for private source address restrictions from external networks.
hostname(config)#ip access-list extended {name | number}
hostname(config-nacl)#deny ip {internal_networks} any log
hostname(config-nacl)#deny ip 127.0.0.0 0.255.255.255 any log
hostname(config-nacl)#deny ip 10.0.0.0 0.255.255.255 any log
hostname(config-nacl)#deny ip 0.0.0.0 0.255.255.255 any log
hostname(config-nacl)#deny ip 172.16.0.0 0.15.255.255 any log
hostname(config-nacl)#deny ip 192.168.0.0 0.0.255.255 any log
hostname(config-nacl)#deny ip 192.0.2.0 0.0.0.255 any log
hostname(config-nacl)#deny ip 169.254.0.0 0.0.255.255 any log
hostname(config-nacl)#deny ip 224.0.0.0 31.255.255.255 any log
hostname(config-nacl)#deny ip host 255.255.255.255 any log
hostname(config-nacl)#permit {protocol} {source_ip} {source_mask} {destination}
{destination_mask} log
hostname(config-nacl)#deny any any log
hostname(config)#interface <external_interface>
hostname(config-if)#access-group <access-list> in
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Impact:
Organizations should plan and implement enterprise security policies that explicitly
separate internal from external networks. Adding 'ip access-list' explicitly permitting and
denying internal and external networks enforces these policies.
Default Value:
No access list defined
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/security/d1/sec-cr-i1.html#GUIDBD76E065-8EAC-4B32-AF25-04BA94DD2B11
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3.2.2 Set inbound 'ip access-group' on the External Interface (Not Scored)
Profile Applicability:
 Level 2
Description:
This command places the router in access-list configuration mode, where you must define
the denied or permitted access conditions by using the deny and permit commands.
Rationale:
Configuring access controls can help prevent spoofing attacks. To reduce the effectiveness
of IP spoofing, configure access control to deny any traffic from the external network that
has a source address that should reside on the internal network. Include local host address
or any reserved private addresses (RFC 1918).
Ensure the permit rule(s) above the final deny rule only allow traffic according to your
organization's least privilege policy.
Audit:
Verify the access-group is applied to the appropriate interface
hostname#sh run | sec interface {external_interface}
Remediation:
Apply the access-group for the external (untrusted) interface
hostname(config)#interface {external_interface}
hostname(config-if)#ip access-group {name | number} in
Impact:
Organizations should plan and implement enterprise security policies explicitly permitting
and denying access based upon access lists. Using the 'ip access-group' command enforces
these policies by explicitly identifying groups permitted access.
Default Value:
No access-group defined
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References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/interface/command/iri1.html#GUID-0D6BDFCD-3FBB-4D26-A274-C1221F8592DF
2. http://www.cisco.com/en/US/docs/ios-xml/ios/security/d1/sec-cr-i1.html#GUIDD9FE7E44-7831-4C64-ACB8-840811A0C993
3.3 Neighbor Authentication
Enable routing authentication.
3.3.1 Require EIGRP Authentication if Protocol is Used
Verify enhanced interior gateway routing protocol (EIGRP) authentication is enabled, if
routing protocol is used, where feasible.
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3.3.1.1 Set 'key chain' (Scored)
Profile Applicability:
 Level 2
Description:
Define an authentication key chain to enable authentication for routing protocols. A key
chain must have at least one key and can have up to 2,147,483,647 keys.
NOTE: Only DRP Agent, EIGRP, and RIPv2 use key chains.
Rationale:
Routing protocols such as DRP Agent, EIGRP, and RIPv2 use key chains for authentication.
Audit:
Verify the appropriate key chain is defined
hostname#sh run | sec key chain
Remediation:
Establish the key chain.
hostname(config)#key chain {key-chain_name}
Impact:
Organizations should plan and implement enterprise security policies that require rigorous
authentication methods for routing protocols. Using 'key chains' for routing protocols
enforces these policies.
Default Value:
Not set
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_pi/command/iri-cra1.html#GUID-A62E89F5-0B8B-4CF0-B4EB-08F2762D88BB
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3.3.1.2 Set 'key' (Scored)
Profile Applicability:
 Level 2
Description:
Configure an authentication key on a key chain.
Rationale:
This is part of the routing authentication setup
Audit:
Verify the appropriate key chain is defined
hostname#sh run | sec key chain
Remediation:
Configure the key number.
hostname(config-keychain)#key {key-number}
Impact:
Organizations should plan and implement enterprise security policies that require rigorous
authentication methods for routing protocols. Using 'key numbers' for key chains for
routing protocols enforces these policies.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_pi/command/iri-cra1.html#GUID-3F31B2E0-0E4B-4F49-A4A8-8ADA1CA0D73F
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3.3.1.3 Set 'key-string' (Scored)
Profile Applicability:
 Level 2
Description:
Configure the authentication string for a key.
Rationale:
This is part of the routing authentication setup
Audit:
Verify the appropriate key chain is defined
hostname#sh run | sec key chain
Remediation:
Configure the key string.
hostname(config-keychain-key)#key-string <key-string>
Impact:
Organizations should plan and implement enterprise security policies that require rigorous
authentication methods for routing protocols. Using 'key strings' for key chains for routing
protocols enforces these policies.
Default Value:
Not set
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_pi/command/iri-cra1.html#GUID-D7A8DC18-2E16-4EA5-8762-8B68B94CC43E
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3.3.1.4 Set 'address-family ipv4 autonomous-system' (Scored)
Profile Applicability:
 Level 2
Description:
Configure the EIGRP address family.
Rationale:
BGP is a true multi-protocol routing protocol and the 'address-family' feature enables
restriction of exchanges with specific neighbors.
Audit:
Verify the appropriate address family is set
hostname#sh run | sec router eigrp
Remediation:
Configure the EIGRP address family.
hostname(config)#router eigrp <virtual-instance-name>
hostname(config-router)#address-family ipv4 autonomous-system {eigrp_as-number}
Impact:
Organizations should plan and implement enterprise security policies that require rigorous
authentication methods for routing protocols. Using 'address-family' for EIGRP enforces
these policies by restricting the exchanges between predefined network devices.
Default Value:
Not set
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_eigrp/command/irei1.html#GUID-67388D6C-AE9C-47CA-8C35-2A2CF9FA668E
2. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_eigrp/command/irea1.html#GUID-C03CFC8A-3CE3-4CF9-9D65-52990DBD3377
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3.3.1.5 Set 'af-interface default' (Scored)
Profile Applicability:
 Level 2
Description:
Defines user defaults to apply to EIGRP interfaces that belong to an address-family.
Rationale:
Part of the EIGRP address-family setup
Audit:
Verify the setting
hostname#sh run | sec router eigrp
Remediation:
Configure the EIGRP address family.
hostname(config)#router eigrp <virtual-instance-name>
hostname(config-router)#address-family ipv4 autonomous-system {eigrp_as-number}
hostname(config-router-af)#af-interface default
Impact:
Organizations should plan and implement enterprise security policies that require rigorous
authentication methods for routing protocols. Using 'af-interface default' for EIGRP
interfaces enforces these policies by restricting the exchanges between predefined network
devices.
Default Value:
Not set
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_eigrp/command/irei1.html#GUID-67388D6C-AE9C-47CA-8C35-2A2CF9FA668E
2. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_eigrp/command/irea1.html#GUID-C03CFC8A-3CE3-4CF9-9D65-52990DBD3377
3. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_eigrp/command/irea1.html#GUID-DC0EF1D3-DFD4-45DF-A553-FA432A3E7233
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3.3.1.6 Set 'authentication key-chain' (Scored)
Profile Applicability:
 Level 2
Description:
Configure the EIGRP address family key chain.
Rationale:
This is part of the EIGRP authentication configuration
Audit:
Verify the appropriate key chain is set
hostname#sh run | sec router eigrp
Remediation:
Configure the EIGRP address family key chain.
hostname(config)#router eigrp <virtual-instance-name>
hostname(config-router)#address-family ipv4 autonomous-system {eigrp_as-number}
hostname(config-router-af)#af-interface {interface-name}
hostname(config-router-af-interface)#authentication key-chain {eigrp_key-chain_name}
Impact:
Organizations should plan and implement enterprise security policies that require rigorous
authentication methods for routing protocols. Using the address-family 'key chain' for
EIGRP enforces these policies by restricting the exchanges between predefined network
devices.
Default Value:
No key chains are specified for EIGRP
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_eigrp/command/irei1.html#GUID-67388D6C-AE9C-47CA-8C35-2A2CF9FA668E
2. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_eigrp/command/irea1.html#GUID-C03CFC8A-3CE3-4CF9-9D65-52990DBD3377
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3. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_eigrp/command/irea1.html#GUID-6B6ED6A3-1AAA-4EFA-B6B8-9BF11EEC37A0
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3.3.1.7 Set 'authentication mode md5' (Scored)
Profile Applicability:
 Level 2
Description:
Configure authentication to prevent unapproved sources from introducing unauthorized or
false service messages.
Rationale:
This is part of the EIGRP authentication configuration
Audit:
Verify the appropriate address family authentication mode is set
hostname#sh run | sec router eigrp
Remediation:
Configure the EIGRP address family authentication mode.
hostname(config)#router eigrp <virtual-instance-name>
hostname(config-router)#address-family ipv4 autonomous-system {eigrp_as-number}
hostname(config-router-af)#af-interface {interface-name}
hostname(config-router-af-interface)#authentication mode md5
Impact:
Organizations should plan and implement enterprise security policies that require rigorous
authentication methods for routing protocols. Using the 'authentication mode' for EIGRP
address-family or service-family packets enforces these policies by restricting the type of
authentication between network devices.
Default Value:
Not defined
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_eigrp/command/irei1.html#GUID-67388D6C-AE9C-47CA-8C35-2A2CF9FA668E
2. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_eigrp/command/irea1.html#GUID-C03CFC8A-3CE3-4CF9-9D65-52990DBD3377
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3. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_eigrp/command/irea1.html#GUID-A29E0EF6-4CEF-40A7-9824-367939001B73
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3.3.1.8 Set 'ip authentication key-chain eigrp' (Scored)
Profile Applicability:
 Level 2
Description:
Specify the type of authentication used in Enhanced Interior Gateway Routing Protocol
(EIGRP) packets per interface.
Rationale:
Configuring EIGRP authentication key-chain number and name to restrict packet exchanges
between network devices.
Audit:
Verify the appropriate key chain is set on the appropriate interface(s)
hostname#sh run int {interface_name} | incl key-chain
Remediation:
Configure the interface with the EIGRP key chain.
hostname(config)#interface {interface_name}
hostname(config-if)#ip authentication key-chain eigrp {eigrp_as-number} {eigrp_keychain_name}
Impact:
Organizations should plan and implement enterprise security policies that require rigorous
authentication methods for routing protocols. Configuring the interface with 'ip
authentication key chain' for EIGRP by name and number enforces these policies by
restricting the exchanges between network devices.
Default Value:
Not set
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/interface/command/iri1.html#GUID-0D6BDFCD-3FBB-4D26-A274-C1221F8592DF
2. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_eigrp/command/irei1.html#GUID-0B344B46-5E8E-4FE2-A3E0-D92410CE5E91
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3.3.1.9 Set 'ip authentication mode eigrp' (Scored)
Profile Applicability:
 Level 2
Description:
Configure authentication to prevent unapproved sources from introducing unauthorized or
false routing messages.
Rationale:
This is part of the EIGRP authentication configuration
Audit:
Verify the appropriate authentication mode is set on the appropriate interface(s)
hostname#sh run int {interface_name} | incl authentication mode
Remediation:
Configure the interface with the EIGRP authentication mode.
hostname(config)#interface {interface_name}
hostname(config-if)#ip authentication mode eigrp {eigrp_as-number} md5
Impact:
Organizations should plan and implement enterprise security policies that require rigorous
authentication methods for routing protocols. Configuring the interface with 'ip
authentication mode' for EIGRP by number and mode enforces these policies by restricting
the exchanges between network devices.
Default Value:
Not set
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/interface/command/iri1.html#GUID-0D6BDFCD-3FBB-4D26-A274-C1221F8592DF
2. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_eigrp/command/irei1.html#GUID-8D1B0697-8E96-4D8A-BD20-536956D68506
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3.3.2 Require OSPF Authentication if Protocol is Used
Verify open shortest path first (OSPF) authentication is enabled, where feasible.
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3.3.2.1 Set 'authentication message-digest' for OSPF area (Scored)
Profile Applicability:
 Level 2
Description:
Enable MD5 authentication for OSPF.
Rationale:
This is part of the OSPF authentication setup.
Audit:
Verify message digest for OSPF is defined
hostname#sh run | sec router ospf
Remediation:
Configure the Message Digest option for OSPF.
hostname(config)#router ospf <ospf_process-id>
hostname(config-router)#area <ospf_area-id> authentication message-digest
Impact:
Organizations should plan and implement enterprise security policies that require rigorous
authentication methods for routing protocols. Configuring the area 'authentication
message-digest' for OSPF enforces these policies by restricting exchanges between network
devices.
Default Value:
Not set
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_ospf/command/ospfi1.html#GUID-3D5781A3-F8DF-4760-A551-6A3AB80A42ED
2. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_ospf/command/ospfa1.html#GUID-81D0F753-D8D5-494E-9A10-B15433CFD445
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3.3.2.2 Set 'ip ospf message-digest-key md5' (Scored)
Profile Applicability:
 Level 2
Description:
Enable Open Shortest Path First (OSPF) Message Digest 5 (MD5) authentication.
Rationale:
This is part of the OSPF authentication setup
Audit:
Verify the appropriate md5 key is defined on the appropriate interface(s)
hostname#sh run int {interface}
Remediation:
Configure the appropriate interface(s) for Message Digest authentication
hostname(config)#interface {interface_name}
hostname(config-if)#ip ospf message-digest-key {ospf_md5_key-id} md5 {ospf_md5_key}
Impact:
Organizations should plan and implement enterprise security policies that require rigorous
authentication methods for routing protocols. Configuring the proper interface(s) for 'ip
ospf message-digest-key md5' enforces these policies by restricting exchanges between
network devices.
Default Value:
Not set
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/interface/command/iri1.html#GUID-0D6BDFCD-3FBB-4D26-A274-C1221F8592DF
2. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_ospf/command/ospfi1.html#GUID-939C79FF-8C09-4D5A-AEB5-DAF25038CA18
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3.3.3 Require RIPv2 Authentication if Protocol is Used
Routing Information Protocol is a distance vector protocol used for interior gateway
routing on some networks.
RIP is a complex protocol, with many configuration options which may have effects which
are not immediately obvious.
Verify routing information protocol (RIP) version two authentication is enabled, if routing
protocol is used, where feasible.
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3.3.3.1 Set 'key chain' (Scored)
Profile Applicability:
 Level 2
Description:
Define an authentication key chain to enable authentication for RIPv2 routing protocols.
Rationale:
This is part of the routing authentication process.
Audit:
Verify the appropriate key chain is defined
hostname#sh run | sec key chain
Remediation:
Establish the key chain.
hostname(config)#key chain {rip_key-chain_name}
Impact:
Organizations should plan and implement enterprise security policies that require rigorous
authentication methods for routing protocols. Configuring the proper authentication 'keychain (name)' for RIPv2 protocols enforces these policies by restricting acceptable
authentication between network devices.
Default Value:
Not set
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_pi/command/iri-cra1.html#GUID-A62E89F5-0B8B-4CF0-B4EB-08F2762D88BB
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3.3.3.2 Set 'key' (Scored)
Profile Applicability:
 Level 2
Description:
Configure an authentication key on a key chain.
Rationale:
This is part of the routing authentication setup
Audit:
Verify the appropriate key chain is defined
hostname#sh run | sec key chain
Remediation:
Configure the key number.
hostname(config-keychain)#key {key-number}
Impact:
Organizations should plan and implement enterprise security policies that require rigorous
authentication methods for routing protocols. Configuring the proper authentication 'key'
for RIPv2 protocols enforces these policies by restricting acceptable authentication
between network devices.
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_pi/command/iri-cra1.html#GUID-3F31B2E0-0E4B-4F49-A4A8-8ADA1CA0D73F
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3.3.3.3 Set 'key-string' (Scored)
Profile Applicability:
 Level 2
Description:
Configure the authentication string for a key.
Rationale:
This is part of the routing authentication setup
Audit:
Verify the appropriate key chain is defined
hostname#sh run | sec key chain
Remediation:
Configure the key string.
hostname(config-keychain-key)#key-string <key-string>
Impact:
Organizations should plan and implement enterprise security policies that require rigorous
authentication methods for routing protocols. Using 'key-string' for key chains for routing
protocols enforces these policies.
Default Value:
Not set
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_pi/command/iri-cra1.html#GUID-D7A8DC18-2E16-4EA5-8762-8B68B94CC43E
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3.3.3.4 Set 'ip rip authentication key-chain' (Scored)
Profile Applicability:
 Level 2
Description:
Enable authentication for Routing Information Protocol (RIP) Version 2 packets and to
specify the set of keys that can be used on an interface.
Rationale:
This is part of the RIPv2 authentication setup
Audit:
Verify the appropriate key chain and mode are set on the appropriate interface(s)
hostname#sh run int {interface_name}
Remediation:
Configure the Interface with the RIPv2 key chain.
hostname(config)#interface {interface_name}
hostname(config-if)#ip rip authentication key-chain {rip_key-chain_name}
Impact:
Organizations should plan and implement enterprise security policies that require rigorous
authentication methods for routing protocols. Configuring the interface with 'ip rip
authentication key-chain' by name enforces these policies by restricting the exchanges
between network devices.
Default Value:
Not set
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/interface/command/iri1.html#GUID-0D6BDFCD-3FBB-4D26-A274-C1221F8592DF
2. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_rip/command/irr-crrip.html#GUID-C1C84D0D-4BD0-4910-911A-ADAB458D0A84
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3.3.3.5 Set 'ip rip authentication mode' to 'md5' (Scored)
Profile Applicability:
 Level 2
Description:
Configure the Interface with the RIPv2 key chain.
Rationale:
This is part of the RIPv2 authentication setup
Audit:
Verify the appropriate mode is set on the appropriate interface(s)
hostname#sh run int <interface>
Remediation:
Configure the RIPv2 authentication mode on the necessary interface(s)
hostname(config)#interface <interface_name>
hostname(config-if)#ip rip authentication mode md5
Impact:
Organizations should plan and implement enterprise security policies that require rigorous
authentication methods for routing protocols. Using the 'ip rip authentication mode md5'
enforces these policies by restricting the type of authentication between network devices.
Default Value:
Not set
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/interface/command/iri1.html#GUID-0D6BDFCD-3FBB-4D26-A274-C1221F8592DF
2. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_rip/command/irr-crrip.html#GUID-47536344-60DC-4D30-9E03-94FF336332C7
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3.3.4 Require BGP Authentication if Protocol is Used
Border Gateway Protocol (BGP)is a path vector protocol used for interior and exterior
gateway routing on some networks.
BGP is a complex protocol, with many configuration options which may have effects which
are not immediately obvious.
Verify Border Gateway Protocol (BGP) authentication is enabled, if routing protocol is used,
where feasible.
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3.3.4.1 Set 'neighbor password' (Scored)
Profile Applicability:
 Level 2
Description:
Enable message digest5 (MD5) authentication on a TCP connection between two BGP peers
Rationale:
Enforcing routing authentication reduces the likelihood of routing poisoning
and unauthorized routers from joining BGP routing.
Audit:
Verify you see the appropriate neighbor password is defined:
hostname#sh run | sec router bgp
Remediation:
Configure BGP neighbor authentication where feasible.
hostname(config)#router bgp <bgp_as-number>
hostname(config-router)#neighbor <bgp_neighbor-ip | peer-group-name> password
<password>
Impact:
Organizations should plan and implement enterprise security policies that require rigorous
authentication methods for routing protocols. Using the 'neighbor password' for BGP
enforces these policies by restricting the type of authentication between network devices.
Default Value:
Not set
References:
1. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_bgp/command/bgpn1.html#GUID-A8900842-ECF3-42D3-B188-921BE0EC060B
2. http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_bgp/command/bgpm1.html#GUID-159A8006-F0DF-4B82-BB71-C39D2C134205
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Control
1
1.1
1.1.1
1.1.2
1.1.3
1.1.4
1.1.5
1.1.6
1.1.7
1.1.8
1.1.9
1.1.10
1.1.11
1.2
1.2.1
1.2.2
1.2.3
1.2.4
1.2.5
1.2.6
1.2.7
1.2.8
1.2.9
1.2.10
1.3
1.3.1
1.3.2
1.3.3
1.4
1.4.1
1.4.2
1.4.3
1.5
1.5.1
1.5.2
Set
Correctly
Yes
No
Management Plane
Local Authentication, Authorization and Accounting (AAA) Rules
Enable 'aaa new-model' (Scored)
Enable 'aaa authentication login' (Scored)
Enable 'aaa authentication enable default' (Scored)
Set 'login authentication for 'line con 0' (Scored)
Set 'login authentication for 'line tty' (Scored)
Set 'login authentication for 'line vty' (Scored)
Set 'aaa accounting' to log all privileged use commands using
'commands 15' (Scored)
Set 'aaa accounting connection' (Scored)
Set 'aaa accounting exec' (Scored)
Set 'aaa accounting network' (Scored)
Set 'aaa accounting system' (Scored)
Access Rules
Set 'privilege 1' for local users (Scored)
Set 'transport input ssh' for 'line vty' connections (Scored)
Set 'no exec' for 'line aux 0' (Scored)
Create 'access-list' for use with 'line vty' (Not Scored)
Set 'access-class' for 'line vty' (Scored)
Set 'exec-timeout' to less than or equal to 10 minutes for 'line aux
0' (Scored)
Set 'exec-timeout' to less than or equal to 10 minutes 'line console
0' (Scored)
Set 'exec-timeout' less than or equal to 10 minutes 'line tty'
(Scored)
Set 'exec-timeout' to less than or equal to 10 minutes 'line vty'
(Scored)
Set 'transport input none' for 'line aux 0' (Scored)
Banner Rules
Set the 'banner-text' for 'banner exec' (Scored)
Set the 'banner-text' for 'banner login' (Scored)
Set the 'banner-text' for 'banner motd' (Scored)
Password Rules
Set 'password' for 'enable secret' (Scored)
Enable 'service password-encryption' (Scored)
Set 'username secret' for all local users (Scored)
SNMP Rules
Set 'no snmp-server' to disable SNMP when unused (Scored)
Unset 'private' for 'snmp-server community' (Scored)
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1.5.3
1.5.4
1.5.5
1.5.6
1.5.7
1.5.8
1.5.9
1.5.10
2
2.1
2.1.1
2.1.1.1
2.1.1.1.1
2.1.1.1.2
2.1.1.1.3
2.1.1.1.4
2.1.1.1.5
2.1.1.2
2.1.2
2.1.3
2.1.4
2.1.5
2.1.6
2.1.7
2.1.8
2.2
2.2.1
2.2.2
2.2.3
2.2.4
2.2.5
2.2.6
2.2.7
2.3
2.3.1
2.3.1.1
2.3.1.2
2.3.1.3
2.3.1.4
2.3.2
2.4
Unset 'public' for 'snmp-server community' (Scored)
Do not set 'RW' for any 'snmp-server community' (Scored)
Set the ACL for each 'snmp-server community' (Scored)
Create an 'access-list' for use with SNMP (Scored)
Set 'snmp-server host' when using SNMP (Scored)
Set 'snmp-server enable traps snmp' (Scored)
Set 'priv' for each 'snmp-server group' using SNMPv3 (Scored)
Require 'aes 128' as minimum for 'snmp-server user' when using
SNMPv3 (Scored)
Control Plane
Global Service Rules
Setup SSH
Configure Prerequisites for the SSH Service
Set the 'hostname' (Scored)
Set the 'ip domain name' (Scored)
Set 'modulus' to greater than or equal to 2048 for 'crypto key
generate rsa' (Not Scored)
Set 'seconds' for 'ip ssh timeout' (Scored)
Set maximimum value for 'ip ssh authentication-retries' (Scored)
Set version 2 for 'ip ssh version' (Scored)
Set 'no cdp run' (Scored)
Set 'no ip bootp server' (Scored)
Set 'no service dhcp' (Scored)
Set 'no ip identd' (Scored)
Set 'service tcp-keepalives-in' (Scored)
Set 'service tcp-keepalives-out' (Scored)
Set 'no service pad' (Scored)
Logging Rules
Set 'logging on' (Scored)
Set 'buffer size' for 'logging buffered' (Scored)
Set 'logging console critical' (Scored)
Set IP address for 'logging host' (Scored)
Set 'logging trap informational' (Scored)
Set 'service timestamps debug datetime' (Scored)
Set 'logging source interface' (Scored)
NTP Rules
Require Encryption Keys for NTP
Set 'ntp authenticate' (Scored)
Set 'ntp authentication-key' (Scored)
Set the 'ntp trusted-key' (Scored)
Set 'key' for each 'ntp server' (Scored)
Set 'ip address' for 'ntp server' (Scored)
Loopback Rules
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2.4.1
2.4.2
2.4.3
2.4.4
3
3.1
3.1.1
3.1.2
3.1.3
3.1.4
3.2
3.2.1
3.2.2
3.3
3.3.1
3.3.1.1
3.3.1.2
3.3.1.3
3.3.1.4
3.3.1.5
3.3.1.6
3.3.1.7
3.3.1.8
3.3.1.9
3.3.2
3.3.2.1
3.3.2.2
3.3.3
3.3.3.1
3.3.3.2
3.3.3.3
3.3.3.4
3.3.3.5
3.3.4
3.3.4.1
Create a single 'interface loopback' (Scored)
Set AAA 'source-interface' (Scored)
Set 'ntp source' to Loopback Interface (Scored)
Set 'ip tftp source-interface' to the Loopback Interface (Scored)
Data Plane
Routing Rules
Set 'no ip source-route' (Scored)
Set 'no ip proxy-arp' (Scored)
Set 'no interface tunnel' (Scored)
Set 'ip verify unicast source reachable-via' (Scored)
Border Router Filtering
Set 'ip access-list extended' to Forbid Private Source Addresses
from External Networks (Not Scored)
Set inbound 'ip access-group' on the External Interface (Not
Scored)
Neighbor Authentication
Require EIGRP Authentication if Protocol is Used
Set 'key chain' (Scored)
Set 'key' (Scored)
Set 'key-string' (Scored)
Set 'address-family ipv4 autonomous-system' (Scored)
Set 'af-interface default' (Scored)
Set 'authentication key-chain' (Scored)
Set 'authentication mode md5' (Scored)
Set 'ip authentication key-chain eigrp' (Scored)
Set 'ip authentication mode eigrp' (Scored)
Require OSPF Authentication if Protocol is Used
Set 'authentication message-digest' for OSPF area (Scored)
Set 'ip ospf message-digest-key md5' (Scored)
Require RIPv2 Authentication if Protocol is Used
Set 'key chain' (Scored)
Set 'key' (Scored)
Set 'key-string' (Scored)
Set 'ip rip authentication key-chain' (Scored)
Set 'ip rip authentication mode' to 'md5' (Scored)
Require BGP Authentication if Protocol is Used
Set 'neighbor password' (Scored)
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149 | P a g e
Appendix: Change History
Date
Version
Changes for this version
07-01-2015
4.0.0
Initial Public Release
150 | P a g e
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